Portable Displays: Resolution ••• What's...

:·~ DISPLAYS FOR PORTABLE PRODUCTS

Portable Displays: High Resolution •••

More Colors • • • What's Next? • In Pursuit ol System LCDs

• Designing Touch LCDs

• RotoView™: A View-Navigation System

• Automotive-Displays Update

• AMLCDs lor Mobile Phones in Japan

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Consumers are demanding more from their cellular phones and PDAs, and that requires more advanced displays. Display makers are working hard to deliver, and we are now seeing small displays with higher resolution, more colors, longer battery life, and high visibility- not to mention integration of electronic components thanks to poly-Si and continuous-grain-silicon displays. And, for portable devices, the display-centric system interface can be as important as the display itself In this issue of ID, our authors look at the state of the art and provide some design guidance.

Next Month in Information Display

Industry Directory Issue o Directory of the Display Industry o LCoS for Rear-Projection HDTV o Preserving Patent Rights o Four-Primary-Color LCDs o CeBIT 2003 Report

Sharp

INFORMATION DISPLAY (ISSN 0362-0972) is pub lished eleven times a year for the Society for Information Display by Palisades Conven tion Management , 41 1 Lafayette St ree t, 2nd Floor, New York, NY 10003; Leona rd H. Kl e in , Pres ident and CEO. EDITORIAL AND BUSINESS OFFICES : Jay Morreale, Managing Editor, Palisades Convention Management, 4 11 Lafayette Street, 2nd Floor, New York , NY 10003; telephone 2 12/460-9700. Send manuscripts to the attention of the Editor. I D. Director of Sales: Joann e Mo rgentha l, Pali sades Conventi o n Manage ment , 411 Lafayette Street, 2nd Floor, New York, NY 10003; 2 12/460-9700. SID HEADQUARTERS, for correspondence on subscriptions and membership: Society for Information Display, 6 10 S. 2nd Street, San Jose, CA 95 11 2; telephone 408/977- 10 13. fax -1531. SUBSCRIPTIONS: Information Display is distributed without charge to those qualified and to SID members as a benefit of membership (annual dues $75 .00). Subscriptions to others: U.S. & Canada: $55.00 one year, $7.50 single copy; elsewhere: $85.00 one year, $7:50 single copy. PRJNTED by Sheridan Printing Company, Alpha, NJ 08865. Third-class postage paid at Easton. PA. PERMISSIONS: Abstrac ting is perm itted with credit to the source. Libraries are permitted to photocopy beyond the limits of the U.S. copyright law for private use of patrons, providing a fee of $2.00 per article is paid to the Copyright Clearance Center, 2 1 Congress Street, Salem, MA 0 I 970 (reference serial code 0362-0972/03/$ 1.00 + $0.00). Instructors are permitted to photocopy isolated articles for noncommercial classroom use wi thout fee. This permisli ion does not apply to any special reports or lists published in this magazine. For other copying, reprint or republication permission, wri te to Society for Information Display, 6 10 S. Second Street, San Jose, CA 95 11 2. Copyright © 2003 Society for Information Display. All rights reserved.

Information JULY 2003 VOL. 19, NO. 7

DISPLAY 2

4

12

Editorial Baloney! And Other Stories from the USDC!Needham Investors Conference

Kenneth I. Werner

MyThrn The Numbers Racket

Peter H. Putman

Sharp: In Pursuit of System LCDs Placing the display electronics - or even the system electronics - on_ the display substrate would revolutionize display-product design; Sharp is making its first "system LCD" products with its own CG Silicon technology.

Joel Pollack

18 Designing Touch LCDs for Portable Devices

22

26

30

The enhanced functionality of portable devices has outpaced the user's ability to view information, execute commands, and easily navigate through complicated menus. The solution is the integration of touch technology with a highly visible display.

Bruce De Visser

A View-Navigation System for Hand-Held Portable Displays RotoView™ scrolling technology makes large virtual images accessible to small hand-held devices such as PDAs and mobile telephones.

David Y. Feinstein

Road Show New technologies and applications are expanding the role of displays in automobiles, helping to inform and entertain both drivers and passengers.

Robert L. Donofrio

Active-Matrix LCDs for Mobile Telephones in Japan The increasingly sophisticated functions of modern mobile telephones require the use of more advanced displays, and the Japanese market leads the way.

Ryoichi Watanabe and Osamu Tomita

42 Letters

45 SID News The SID Senior Member Grade Committee announces more SID Senior Members.

47 Sustaining Members

47 Advertiser's Index

48 Backlight DuPont Displays: Forcing the Action

David Lieberman

48 Calendar of Display-Related Events

For Industry News, New Products, Forthcoming Articles, and Complete, Continually Updated Conference Calendar, see www.sid.org.

Information Display 7103 1

Baloney! And Other Stories from the USDC/Needham Investors Conference

The USDC/Needham Display Industry Investors Conference was held in New York City on March 18, 2003, the day after Three-Five Systems (TFS) announced the spin-off of its microdisplay business into a separate company to be called Three-Five Microdisplay, Inc. (TFMD). So, when President and CEO Jack Saltich stepped to the podium to give the

TFS presentation instead of EVP Jeffrey Buchanan (as stated in the program), it was no surprise that he was speaking to a packed room.

Saltich was effective, saying that TFS today is really two separate companies: Integrated Systems and Displays (lSD), which is a service-oriented company, although it does sell products, and the LCoS business, which is still developing. Most of the company's losses have been in the LCoS business, not the core business . The company's strategy is to be a display-centric EMS provider, and recent acquisitions of a Boston-based GPS company and a Redmond-based systems-manufacturing company are furthering that goal, Saltich said.

Concerning TFMD, Saltich said he still believes that LCoS will be the next low-end HDTV technology, but the two businesses have different growth characteristics, different strategic parameters, different core deliverables, different markets and customers, and different employee skills and perspectives. "As separate companies, there will be many more degrees of freedom to exploit different strengths." The plan is for TFS to capitalize TFMD to the tune of approximately $20 million and for Saltich to become Chairman of the Board. Bob Melcher will move over to TFMD to become CTO.

After his talk, I spoke with Saltich privately and asked him one question: "You delivered a graceful presentation, but there will be some skeptics who will say that the microdisplay business is a turkey and you are just trying to dump it. Comment?"

Saltich's answer began explosively: "Baloney! Ifl thought it was a turkey, I'd just close it down, not invest 25% of my cash in the new company and become its Chairman. We would have feathered down investment 12 months ago. I believe in this technology. Two years ago, I was less of a believer in NTE than I am now ... we now have customers." Saltich added that he is actively looking for a CFO for the new company.

Investment in Displays? The conference was well attended, and there seemed to be a real interest in display opportunities among the substantial investment contingent gathered at the Grand Hyatt Hotel. Several speakers quoted figures to the effect that displays accounted for a large percentage of the overall electronics market- nearly as large as semiconductors - and was the fastest growing segment, bar none.

I asked Jim Ricchiuti, a principal at Needham & Company, about the apparent excitement. He said that in a largely stagnant world economy, anything that's growing rapidly, as displays are, will capture the interest of the investment community. But institutional investors "are looking for investment opportunities in established display companies. Emerging companies are of much more limited appeal."

continued on page 44

2 Information Display 7103

Information

DISPLAY Editor: Kenneth I. W emer Managing Editor: Jay Morreale Administrative Editor: Dian Mecca Administrative Assistant: Ralph Nadell Contributing Editors: David Lieberman, Bryan Norris, Alfred Poor, Advertising Manager: Jay Morreale Sales Manager: Joanne Morgenthal

Regional Associate Editors

Allan Kmetz (Americas) Chatham, New Jersey

Shigeo Mikoshiba (Asia) University of Electro-Communications Tokyo, Japan

Alan Mosley (Europe) Central Research Laboratories Hayes, Middlesex, U.K.

Advisory Editors

Carl Machover Mac hover Associates White Plains, New York

Alan Sobel Consultant Evanston, Illinois

Webster E. Howard Lagrangeville, New York

Ernst Lueder University of Stuttgart Stuttgart Germany

Sungkyoo Lim Information Display Research Center Choongnam, Korea

The opinions expressed in editorials, columns, and feature articles do not necessarily reflect the opinions of the editor or publisher of Information Display Magazine, nor do they necessarily reflect the position of the Society for Information Display.

I h¢1 i! I iii The Numbers Racket

by Peter H. Putman, CTS

Pity the poor consumer. For years, buying a TV set meant buying a "TV" set, and nothing more. All one had to do is connect an antenna or cable, tum on the power, and start watching. Viewers didn' t need to concern themselves with "native resolution" and "pixel decimation."

Thanks to a major transformation of television broadcasting, the days of analog 525- and 625-line interlaced-scan images are numbered. Replacing them will be several digital picture formats that offer as much and more resolution in two different screen shapes and sizes.

That's a lot for the average consumer to absorb, even after repeated visits to Best Buy and Circuit City. But there 's another layer of complexity added with fixed-pixel displays . Now, our would-be TV buyer has to deal with different pixel counts; some of which match the new DTV standards, and some of which come out of left field .

In an attempt to clear things up, the Consumer Electronics Association has developed definitions for TV sets and monitors. As a result, we now have standard-definition TV (SDTV), enhanced-definition TV (EDTV), and high-definition TV (HDTV). These standards are based on specific scan-line counts, which ought to translate easily to fixed-pixel arrays.

While the difference between a monitor and TV is obvious (the latter has a built-in digital TV tuner), the differences between SDTV and EDTV are not so clear. Consider a 42-in. 16 x 9 plasma monitor with 852 x 480 pixels. Judging by vertical pixel count, it is an SDTV monitor. But horizontal pixel count of 852 is far more than a plain vanilla TV offers, so many folks consider this an EDTV monitor, particularly since it supports 480p, too.

Another puzzler: 42-in. plasma panels that employ 1024 x 768 non-square pixel matrices. Are these EDTV or HDTV monitors? Although 768 vertical pixels are certainly more than 720, 1024 horizontal pixels are less than 1280. And while a matrix of 1024 x 768 pixels produces a 4:3 picture aspect ratio, the screens on these monitors measure 16 x 9!

And what about the 32- and 42-in. ALiS plasma monitors and TVs sold by Sony, Fujitsu, and Hitachi that sport native pixel counts of 852 x 1024 and 1024 x 1024, respectively? Are these EDTV displays? HDTV? or something in the middle?

Do not look to the computer industry for help. That same 852 x 480 plasma monitor is known as a wide VGA (WVGA) in the computer world, not EDTV or SDTV. LCD and plasma monitors with 1280 x 768 and 1365 x 768 resolution are called wide XGA by the PC industry, not EDTV or HDTV. And 1024 x 768 monitors with non-square pixels are not even on their radar yet.

Most consumers will likely plug their ears and avoid this discussion altogether, particularly when they discover that any and all of these TVs and monitors can display HDTV signals, albeit with varying degrees of pixel decimation. And those pictures will look pretty darn good, too.


4 Information Display 7/03

SID Executive Committee President: A. Kmetz President-Elect: S. Mikoshiba Regional VP, Americas: M. Anandan Regional VP, Asia: M. H. Oh Regional VP, Europe: J-P. Budin Treasurer: R. Seery Secretary: P. Drzaic Past President: A. Silzars

Directors Bay Area: N. Balram Beijing: B. P. Wang Belarus: A. Smimov Canada: T. C. Schmidt Dayton: D. G. Hopper Delaware VaUey: J. W. Parker ill Detroit: R. L. Donofrio France: M. Hareng Hong Kong: H. Leung India: K. R. Sarma Japan: M. Maeda Korea: M. K. Han Los Angeles: P. C. Baron Mid-Atlantic: A. Ghosh Mid-Europe: J. Kimmel Minneapolis/St. Paul: H. V. Holec New England: W. A. Hamilton Pacific Northwest: J. A. Rupp Russia: V. V. Belyaev San Diego: T. Iki Singapore/Malaysia: B. A. Ghani Southwest: P. A. Smith Taipei: F-C. F. Luo Texas: Z. Yani v U.K. & Ireland: A. Mosley Ukraine: V. Sorokin

Committee Chairs Academic: H. Uchiike Archives/Historian: D. Dumont Bylaws: E. Lueder Chapter Formation: B. Needham Communications: H. Hoffman Convention: P. M. Heyman Definitions & Standards: D. Hopper Honors & Awards: L. F. Weber Long-Range Planning: T. Iki Membership: R. Kessler Nominations: A. Silzars Publications: E. Stupp

Chapter Chairs Bay Area: M. F. Flynn Beijing: J-L. Zhu Belarus: S. Yakovenko Canada: A. Kitai Dayton: J . C. Byrd Delaware Valley: S. Kalatucka, Jr. Detroit: S. Pala France: R. Meyer Hong Kong: H. S. Kwok India: S. Kaura Japan: S. Naemura Korea: L. S. Park Los Angeles: M. L. Kesselman Mid-Atlantic: V. R. Capozzi Mid-Europe: N. Fruehauf Minneapolis/St. Paul : E. L. Tomczak New England: S. P. Atwood Pacific Northwest: T. Voutsas Russia: l. N. Kompanets San Diego: A. R. Wilson Singapore/Malaysia: X. Sun Southwest: D. S. Lowe Taipei: H.-P. D. Shieh Texas: R. L. Fink U.K. & Ireland : J . A. Raines Ukraine: V. G. Sorokin

Office Administration Office and Data Manager: Jenny Needham

Society for Information Display 610 S. 2nd Street San Jose, CA 95 11 2 408/977-101 3, fax -153 1 e-mail: [email protected] http://www.sid.org

fi'?1t§i•i·'!Oifl•l--------------------

Sharp: In Pursuit of System LCDs

Placing the display electronics - or even the system electronics- on the display substrate would revolutionize display-product design; Sharp is making its first "system LCD " products with its own CG Silicon technology.

by Joel Pollack

L E system liquid-crystal display (LCD) has come to be con idered the ideal display component for high-performance mobile applications. By definition, a system LCD is manufactured to combine a number of component cun·ently fabricated as discrete elements onto a single LCD glass substrate. The e components may include the LCD driver. VO . CPU, shift registers, graphic controllers. operational amplifiers (op amps). de-to-de converters, touch-panel controllers. SRAM. DR AM. and EEPROM. It is also possible for the glas substrate to contain components for ignal proces ing/computation. data torage.

and communication . Recent advances in manufacturing proces es

are now allowing LCD maker to take the fi rst steps toward attaining the goal of a system LCD. These advances are een as key to attaining a new generation of electronic mobile devices that are compact. rugged, lightweight. powerful, and energy efficient. In the meantime. these same innovations in manufacturing are making available di play that have high resolution. brilliant color and brightness in any lighting condition, and low power consumption. These new displays are already being de igned into today's mobile device .

A number of LCD manufacturers. including Sanyo, Sharp, Sony. and Toshiba. are con-

Joel Pollack is Vice President of the Display Business Unit at Sharp Microelectronics of the Americas, 5700 N. W. Pacific Rim Blvd. , Camas, WA 98607-9489: Telephone 360!834-8926,fax 360/834- 992, e-mail: joel.pollack@ shmpusa. com.

12 biformarion Displav 7103

ducting R&D ac ti vities in search of the best way to combine system components onto a

single LCD glass subsu-ate. These efforts have brought significant innovations to cur-

Sharp

Fig. 1: Sharp 's Advanced TFT-LCD module, which has been in production since April 2002, is incorporated in such products as the Sharp CX 10 mobile phone mamifacruredfor Vodaphone.

0362-0972/03/1907-012$1.00 + .00 © SID 2003

rent amorphous-silicon (a-Si) processes, have led to the introduction of the low-temperaturepolysilicon (LTPS ) process, and, most recently. have led Sharp to introduce displays manufactured in a continuous-grain- ilicon (CG Silicon) process.

Amorphous Silicon Since the introduction of thin-film-transistor LCD (TIT-LCD ) in 1973 and the sub equent productization of this technology. LCD manufacturing has been accomplished primarily by using an a-Si process. Over the yem·s, advances in a-Si di plays have resulted in marked improvements in productivity. color. contrast. viewability. and response rates. Today. the e di plays are suitable for active-matrix displays in notebook computer . LCD TYs. industrial applications. and ponable devices.

A key advance in small sizes has been the development of transflective displays ba ed on the a-Si manufacturing process. Shm·p·s Advanced-TIT technology. for example. is a proprietary technology employing reflectivedisplay characteristics for bright outdoor setting while at the same time utilizing trans-mi sive display characteristics in indoor environments (Fig. I ). nlike other tran flecti ve products. Sharp 's Advanced-TIT technology employ differential cell-gap control and color filters optimized for transmissive and reflective characteri tic in the corresponding regions of the display pixels . This design avoid the compromises in transmissivity and contra t that m·e seen in conventional tran -flective products. Color rendering remains essentially unchanged whether the display is viewed indoors or outdoors, making the e di plays well suited for PDA . mobile phones, and wirele device .

Despite their versatility. one of the weakest links in today' a-Si TITs. and where mo t failure occur. is the tab bond - the attachment of the driver ICs to the TIT bu bm· . If the tab could be eli minated. it would be possible to manufacture a product that i more rugged than typical TITs .

One alternative is chip-on-glass (COG) technology. which i now used for many automotive applications. The COG proces connects the LCD controller directly to the LCD gla . without the need for tab-bonding connections, and thereby provides significant ruggedization for these application . The result i a very compact. thin. and lightweight module. The latest versions of the Palm Pilot

Sharp

Fig. 2: In !me 2002, Sh01p announced the successful integrarion of its first sysrem LCD, an 8-bit Z80 CPU, onto a glass substrate designed for LCDs. The system uses CG Silicon technology.

utilize COG technology to better enable these units to withstand the hock of being dropped.

Manufacturers can a! o make field-effecttransistor (FET) arrays of very high density, but there is a limit to the interconnect density. which makes driving these array a challenge. The limiting density of the interconnect to a-Si displays has essentially been reached; it is not reliable to use a tab bond or a COG bond above a certain density.

Yet another problem common to a-Si displays relate to the gate delay cau ed by the select-line resistivity . These lines form resi -ranee-capacitance tran mission lines that delay and diston the gate pulses- effects that limit the ultimate size of an ac tive-matrix display. Typically, a-Si TIT fabrication processes have used thin high-re istivity refractory metals which have exacerbated the resistivity problem. To realize larger-area displays, new metallization y tern were developed. a-Sia! o doe little to addres the is ue of external YLSI drive electronics. which are becoming the largest component co t in an LCD system.

Manufacturing Advances In order to addre s the e key concerns about a-Si technology, display makers began researching various forms of L TPS processes

for u e in LCDs. L TPS technology promised to become an attractive alternative for producing LCDs becau e it can be used to fabricate driver circuits on the glass substrate at the same time as the pixel-drive FETs. Poly-ilicon can achieve a quasi-crystalline struc

ture that enables higher electron carrier mobility when it i deposited and annealed at a temperature above 600°C, deposited on a qumtz substrate, and fabricated on a metal-oxide-emiconductor (MOS) line. ln fact. the be t

L TPS can attain a carrier mobility that i 200 times that of a-Si. AMOS line permits smaller design rule for the circuits and higher-resolution di plays.

The mo t commonly available LTPS technology, in production the longest. is known a n-channel or NMOS. In the MOS process, the transistor contain a channel (the region separating the ource and drain) that i comprised of an n-type semiconductor. An n-type emiconductor i distinguished by the density

of hole in the valence band being exceeded by the den ity of electrons in the conduction band. In n-type semiconductors. electron are the majority carrier and hole are the minority carrier . This n-type behavior is induced by the addition of donor impurities, such a arsenic or phosphorus, to the crystal structure of silicon.

InformaTion Display 7103 13

system-on-LCD

Complementary MOS (CMOS), the second form of L TPS, uses both an n-channel and a p-channel. In the CMOS process, the transistors contain a channel that is made of a p-type semiconductor, distinguished by the density of electrons in the conduction band being exceeded by the density of holes in the valence band. In p-type semiconductors, holes are the majority carriers and electrons are the minority carriers. This p-type behavior is induced by the addition of acceptor impurities, such as boron, to the crystal structure of silicon. The combination of both nand p-channel processes produces a push-pull effect, enabling higher electron carrier mobility than a simple n-channel process. However, this combination also requires more masking steps and is far more complex to manufacture.

Although the NMOS process requires only a limited number of layers, it brings with it a number of limitations. Circuitry built with an NMOS process has limitations in operating speed that limit these designs to QVGA-orsmaller displays. The power consumption of NMOS circuits is higher than more recent CMOS processes. The area necessary for an NMOS circuit is typically larger than that for an equivalent CMOS circuit, so NMOS technology is not compatible with the typical requirements of mobile products (low power consumption and small bezel area). In addition, for a given power-supply voltage, an NMOS-based circuit will respond slower than a CMOS-based circuit, leading to the limitation of quarter-VGA LCDs.

Although some benefits can be attained using L TPS, manufacturers must overcome a

number of challenges. First and foremost , all processing must be conducted at a thermal budget compatible with low-cost standard glass, i.e., the glass can not become so hot that it softens and loses its mechanical stability. In addition, equipment for the additional processes must be introduced and optimized to perform such tasks as reduced H-content silicon deposition, crystallization, ion-doping, gate dielectric film formation, and hydrogenation.

Continuous-Grain Silicon As a result of searching for solutions to these problems, Sharp Corp. recently introduced a new technology called continuous-grain silicon (CG Silicon), a patented technology developed jointly by Sharp and Semiconductor Energy Laboratory Co., Ltd. Unlike a-Si

Table 1: Comparative Performance ofLow-Temperature-Polysilicon, Amorphous-Silicon, and Continuous-Grain-Silicon Displays

Display type

Display active area (mmxmm)

Display diagonal (in.)

Number of pixels

Dot pitch/pixels per inch (mm/ppi)

Outline (mm x mm x mm)

Luminance (cd/m2)

Multi-resolution/colors 18 bit<=> 3-bit digital RGB

Drivers

Functions

Input signal

Power consumption (m W)


3.7- and 4.0-in. Continuous-Grai!l·Silicon Panels

CG Silicon Display

LQ037V7Dxx

Transflective

56.16 X 74.88

3.7

480 x RGB x 640

0.039 x 0.117 I 217

65 X 89.8 X 4.2

60

VGA/260k QVGA/260k QVGA I 8 color

Source driver/discrete Gate driver/monolithic

Multi-resolution Partial display operation Mirror-image scanning; x and y directions

6-bit digital

VGA: 77* QVGA: 25

CG Silicon Display

LQ040V7Dxx

Transflecti ve

60.48 X 80.64

4.0

480 x RGB x 640

0.042 x 0.126 I 202

69.3 X 96 X 4.2

60

VGA/260k QVGA/260k QVGA I 8 color


Multi-resolution Partial display operation Mirror-image scanning x and y directions

6-bit digital

VGA: 77* QVGA: 25

"Not including backlight power consumption.

L TPS Display

4.0-in. LPS

Transmissive

80.64 X 60.48

4.0

640 x RGB x 480

0.042 X 0.126 I 202

94.04 X 69.98

30

VGA/260k


VGAonly

6-bit digital

VGA: 380

a-Si Display

LQ035Q7DB02

Transflective

53 .64 X 71.52

3.5

240 X RGB X 320

0.0745 X 0.2235 I 113

65 X 85 X 4.5

50

QVGA /260k only

Source driver/discrete Gate driver/discrete

QVGA only

6-bit digital

QVGA: 35*

and poly-Si, CG Silicon aligns its silicon grains with continuous atomic-level continuity at the grain boundaries. This continuity permits electrons to travel across the semiconductor at a carrier mobility of 300 cm2N -sec, which is approximately 600 times faster than that of a-Si and approximately three times faster than the best LTPS. This enhanced electron mobility, which comes far closer to that of single-crystal silicon (600 cm2N -sec), opens the door to building CPUs, memory drivers, digital/analog converters, and other peripherals onto the same substrate as the display.

Although Sharp has developed displays using LTPS, it has now committed its manufacturing resources to the new CG Silicon process because CG Silicon enables the manufacture of highly integrated panel circuitry and substrates in a low-temperature process. The CG Silicon manufacturing process also has the same number of layers as an n-channel process, which makes it simple and efficient, with high yields.

The key to CG Silicon technology is the crystallization step that yields the high-quality active layer which is used to build the TFfs. Starting with a display-grade glass (such as

Coming 1737 alumina silicate glass), a layer stack is deposited, consisting of basecoat film and a-Si film. A metal catalyst is introduced into the a-Si film , which is then subjected to crystallization in order to nucleate and grow high-quality crystal domains in the film. Typically, a combination of solid-phase crystallization and laser annealing is used to achieve the high-crystal-quality poly-Si film.

TFfs are then built using a CMOS fabrication flow that involves simultaneous fabrication of pixel and driver transistors on the glass substrate. This fabrication flow is now compatible with display-grade glass substrates because the maximum process temperature does not exceed 600°C.

CG Silicon, being relatively easier to manufacture and producing even better viewing characteristics than L TPS, is a technology that will enable the creation of a system LCD. For example, handheld devices typically require special graphics controllers and a multiplex controller. The goal, instead of using two separate chips on the motherboard, is to eventually integrate these functions and control electronics into the CG Silicon panel. By integrating the many system functions into the

single panel, the total system cost can be reduced, and system reliability and image definition can be increased (Fig. 2) .

A key feature of the system-LCD architecture is the ability to dynamically control the resolution and color depth of the display according to the data to be displayed. Because the drivers are not discrete elements, there is nothing to deter the manufacturer from placing VGA drivers on one end of the display's column bus bars and QVGA drivers on the opposite end.

This proprietary Multi-Driver technology enables Sharp to develop displays that can operate in three principal modes: full-color VGA, full-color QVGA with 65 ,536 colors, and monochrome QVGA. These high-transmissivity LCDs are designed with reflective electrodes in the pixel regions that do not transmit light. The electrodes further boost screen brightness by reflecting ambient light, which provides significantly better viewability in outdoor settings under bright, sunny conditions.

One other feature that can be incorporated into the display is ultra-low power consumption, which allows the average power con-

Table 1: Comparative Performance of Low-Temperature-Polysilicon, Amorphous-Silicon, and Continuous-Grain-Silicon Displays (continued)

LCD type

Display active area (mmxmm)

Display diagonal (in.)

Number of pixels

Dot pitch (mm) I ppi

Outline (mm)

Luminance (cd/m2)

Colors

Drivers

Input signals

Power consumption (W)

7.1 - and 7.4-in. Continuous-Grain-Silicon Panels

CG Silicon CG Silicon Display Display L TPS Display a-Si Display

LS071X7LAOI LS074KLxx 6.3-in. LPS LQ065Y5DG01

Highly transmissive Highly transmissive Transmissive Transmissive advanced; sunlight readable advanced; sunlight readable Not sunlight readable Not sunlight readable

144 X 108 161 X 96.8 129 X 96.8 130.4 X 78.24

7.1 7.4 6.3 6.5

1024 x RGB x 768 1280 x RGB x 768 480 x RGB x 640 800 x RGB x 480

0.047 x 0.141 I 180 0.042 x 0.126 I 202 0.042 X 0.126 I 202 0.06 x 0.163 I 156

169 X 122 X 3.6-6.8 183.4 X 116.2 X 3.5-6.5 151.9x 115.8 x 7.3 157.2 X 89.7 X 8.4

180 180 150 350

260k 260k 260k 260k

Source driver/discrete Source driver/discrete Source driver/discrete Source driver/discrete Gate driver/monolithic Gate driver/monolithic Gate driver/monolithic Gate driver/discrete

6-bit digital 6-bit digital 6-bit digital 6-bit digital

< 3.2 <3.4 3.2 4

Information Display 7/03 15

system-on-LCD

Sharp

Fig. 3: Among the first products that incorporate the system-LCD architecture are Sharp digital Viewcam camcorder models VL-Zl U, VL-ZJU, VL-Z5U, and VL-Z7U, which are equipped with 2.5-in. color CGS screens.

umption of the display to be reduced while till allowing the display to deliver high per

formance when requi red. This feature allow the display to be operated in a statu mode, a simple graphics mode, and full -video mode, each at different power levels. The power consumption of Sharp's 3.7-in. display, for example, is only 14 mW for YGA/full-color for graphics 8 mW for QVGA/full-color, and 2 mW for QVGA/monochrome in a status mode (Table 1).

CG Silicon technology is driving the development of a new generation of smaller, thinner, more versatile, more powerful. and more energy-efficient mobile devices. The first CG


Silicon product demonstration was a 2.6-in . monochrome high-temperature panel with a re olution of 1280 x 1024 pixel . After further refinement, Sharp demonstrated the first prototypes of a low-temperature CG Silicon process in January 200 I, heralding the creation of larger LCD panels using glass substrates. At the same time, the company announced it was investing approximately $427 million to convert its "NFI" line in Tenri , Japan, from manufacturing a-Si displays to manufacturing the fir t commercial CG-Silicon-ba ed TFT displays. The first products that incorporate the system-LCD architecture include Sharp" Zaurus SL-C700

that is available in Japan, along with four digital Yiewcam camcorders equipped with 2.5-in. color CG Silicon screens (Fig. 3).

Sharp anticipate that further evolution of CG Silicon- to an electron mobility of over 500 cm2/Y -sec- will permit the integration of high-speed circuits onto the TFT sub-trate. This will bring closer the ultimate goal

of a complete y tem-on-panel that makes possible paper-thin multimedia laptops and powerful. multi-function credit-card- ized devices.

The Potential of CG Silicon When combined with technologies such as reflective color TFT-LCD and Advanced TFT-LCD, which provides high viewability in both bright and dark environments, CG Sili con allows OEM and developers to differentiate themselves from competitor and enables the production of LCDs with high added value. Developers till have a long way to go before they extract all the perfom1ance gains possible from CG Silicon.

Initially, new CG Silicon components will take the form of op amps and graphics controllers. but the technology will al o support touch-panel controllers and perhap . omeday. the entire microcontroller (MCU) on the panel. The ability to expand on these concepts is limited only by the imagination.

More research i certainly warranted in the area of LCD technologies, but Sharp' research suggests that CG Silicon holds great potential for allowing engineers to integrate components such as the LCD driver circuitry and the controller ICs on the same glass ubstrate as the LCD panel while simultaneously delivering a better user experience to consumers. •

SID '04 Symposium, Seminar,

and Exhibition

Seattle, Washington

Washington State Convention and Trade Center

May 23-28, 2004

Designing Touch LCDs for Portable Devices

The enhanced functionality of portable devices has outpaced the user's ability to view information, execute commands, and easily navigate through complicated menus. The solution is the integration of touch technology with a highly visible display.

by Bruce De Visser

ERT ABLE electronic device have made revolutionary change in our daily live . From mobile telephone to per onal digital a sistants (PDAs) . these battery-powered marvels perform a wide range of useful applications. While telephones can get by with a numeric keypad and a few extra buttons, PDAs and rel ated device must convey more information and provide a more versatile control system. As a result, mo t rely on a liquidcrystal-di play (LCD) screen with a touch panel to provide an intuitive, graphical man- machine interface (MMI) commonly called a graphical user interface (GUI).

The trend to incorporate a touch GUI has expanded to encompass products that previously did not use an LCD and those that had LCDs but no touch interface. Examples include medical monitor , electronic control systems, and various instrumentation applications.

Typically, a popular point at which to introduce a GUJ is at the inception of a new design. The evolution of a product design to a new model and the updating of a current design are also good points to consider adding the touch-GUI component. Regardless of the

Bruce De Visser is Producr Markering Manager for Touch Input Devices at Fujitsu Componenrs America, Inc., 250 £. Caribbean Dr., Sunnyvale, CA 94089; telephone 4081745-4928, fax 4081745-4971 , e-mail: [email protected]. He has more than 20 years experience in man- machine inrerface analysis, design, and implementation.

18 hiformarion Display 7103

product stage. the design team will face many technology choice . But independent of technology, the optical-design goal of the product must remain the paramount concern.

Design for Touch Original-equipment manufacturers (OEMs) continually strive to satisfy user demand for additional features, enhanced functionality , and ea e of use. For most users , "ease of use'' relates directly to the quality of the user interface . Since the primary user intetface in the portable market egment is the touch display, marketers define a highly vi ible display as a key element. This translates into an engineer-

Hard coat ...

ITO layer ..

ITO layer ...

ing design requirement. and achieving it becomes one of the main project goal , especially con idering that the LCD is often a topco t item.

Designers select the LCD primarily based on modes of use, battery-life requirements, competitive goal relative to display appearance and performance, and -most certainly cost. After the designers complete the lengthy and involved proces of choo ing the di play, they must then select a touch panel. For many engineering-team members, this is a new experience and therefore a learning opportunity: for some other . it i an iteration in the proce s of life a a product -de ign engineer;

Film

Spacers-.

Glass

Fig. 1: The resistive touch panel is the most popular for portable applicazions. Its basic construction consists of a glass panel, an ITO resisrive coating applied to rhe glass, spacer dots, an ITO resistive coating applied to the film, a flexible plastic film, and a hardcoat applied to the film.

0362-0972/0311907-018 1.00 + .00 © SID 2003

and a small but growing group realize this will be an extension of the LCD criteria.

The growth of the portable-device market -a with any new or expandi ng product areacreates new design opportunities that engineers might not yet have experienced. This is one of the positive benefits of involvement in product design; the constantly changing set of challenges offers continuing opportunities to learn something new.

Application Requirements Presenting adequately viewable information on a portable device's display can be a sign ifi cant challenge. High-ambi ent-light levels from fluorescent or incandescent fixtures, sunlight conling through the window. reflected light from windows, or a combination of sources- can make it difficult or impossible to read a display. Whether the display is color or monochrome, marketplace acceptance depends heavi ly on the user's ability to see the information on the screen .

LCD brightness levels can be increased through back and front lighting and other enhancements to achieve the desired readability. But when a touch panel is added to the LCD, the resulting optical stack can produce various effects, some of which may be interesting. but none are desirable. These typically include reduced light transmission, ambient and spot-lighting reflections, and distracting pattems produced by optical interference between the various layers.

The solution to these problems consist of choosing appropriate basic touch-panel components and adding various optical treatments that can provide significant improvement. Although any additional materials or processes inherently add cost - sometimes substantial cost - thi s must be weighed against the cost of product failure. The goal must be a product that performs to the designer" s requirements at a reasonable cost. Fortunately, designers can often achieve thi s without resorti ng to expensive methods .

Picking Parameters The most popular type of touch panel for portable applications is the fi lm-on-glass analog resistive panel. Re istive touch panels (RTPs) offer several choices of product properties, such as pen-and-finger or pen-only operation, tail length and position. and actuation force. For this discussion, we will focus on the choices that affect optical performance.

Apollo Display Technology and Opt rex America

Fig. 2: The clear resistive touch pane/from Fujitsu has 86% light transmission and minimal effect on the color and clarity of the Optrex 6.4-in. TFT-LCD located behind it.

The RTF' s basic bottom-to-top-layer construction consists of a glass panel, an ITO resistive coating applied to the glass . spacer dots. an ITO resistive coating applied to the film. a flexible plastic film- usually polyethylene terephthalate (PET) - and a hardcoat applied to the film (Fig. l ). For many of these items, there are commonly available choices.

• Glass type: Normal (soda) glass or chemically strengthened (CS) glass.

• Glass thickness: Typically 0.7 or 1.1 mm for portable applications, although the available range extends from 0.55 to 1.8 mm.

• ITO: A variety of color effects are avai lable.

• Hardcoat: Clear or anti-glare (AG) surface.

The optical transmissivity (or "transparency") of the resulting combinat ions typically falls in the range of 78-82%, although higher values are available.

The glass choices are relatively simple: Thinner is better for weight and optical requirements as long as strength goals are met. Glass strength, however. is an area that is often not defined because it is difficult to

accurately characterize the user environment, and glass strength ends up being evaluated empirically through user trials . Typically, LCD sizes under 4 in. use 0.7-mm glass, and other portable applications use 1.1-mm gla s.

The ITO choices are not often a concern because vendor samples can be used to determine if there is any undesired coloration from the chosen product range. In the case where a specific color change is desired, it is very helpful to provide a working LCD sample to the RTP vendor. Thi s will help the vendor select the most appropriate ITO coating to meet color goals for the specific LCD- RTP assembly.

The hardcoat is the protective finish applied to the exterior of the plastic-film layer, and there are two basic types: clear and anti-glare (AG). Clear hardcoat has a minimum effect on the LCD image, although there is always some measurable effect from any additional optical layer. Clear hardcoat has the disadvantage of first-surface glare, and it is scratched more easily than AG hardcoat. Clear hardcoat is the most prevalent choice for reflecti ve applications becau e it does not scatter or diffuse the 1 ight. It is also becoming


touch-LCD design

Hard coat Film

ITO layer IM (AR) coat/

~ Spacers ---.... ITO layer ..

~--------------------------~ IM (AR) coat/

Glass IM (AR) coat ~-----....___ ________ ____J

Fig. 3: Index-matching (or anti-reflection) coatings applied to the touch panel 's surfaces significantly reduce internal light reflections within a resistive touch panel, resulting in improved visibility of the LCD surface and transmissivity of up to 92%.

popular for transflective- and some transmissive-LCD uses.

AG hardcoat is used to reduce first-surface reflections, commonly termed glare. It is also referred to as "white shirt" or "mirror effect." Optically, AG hardcoat scatters part of the light reflecting off the surface. The image on the LCD is also diffused, unfortunately, which the viewer perceives as reduced contrast. This effect increases significantly as the distance between the LCD surface and the RTP increases.

AG hardcoat also results in a reduced viewing angle, although this is apparent mainly at extreme viewing angles and is not a concern in most cases. AG hardcoat also provides the best resistance to scratching, which is an important consideration if a stylus is used as the primary input device. Finally. AG hardcoat can be effectively treated to embody antismudge (AS) properties. This can be valuable where oily fingerprints could build up and interfere with LCD visibility, as with automotive diagnostic tools.

Determining the Optimum Solution Choosing the best design solution requires a consideration of several factors , so a welldefined specifications or requirements list will aid engineers immensely in making choices. Even those items not easily measured, such as "good user di play readability outdoors," are valuable criteria. No matter how much defini-

20 lnformarion Display 7103

tion is provided, adequate time should be spent testing and reviewing samples with other decision-makers in the organization. No matter how well a product meets its specifications, if it does not satisfy user requirements, the design is not finished.

A good starting point is to determine up front whether a clear or AG hardcoat is required. This will save time becau e other more advanced choices depend upon this. A basic rule is that if reflections can realistically be avoided by positioning the device, then a clear hardcoat is the primary choice (Fig. 2). It also provides better viewing clarity than AG hardcoat for the same transmissivity value because the light is neither scattered or diffused.

However, a reflection that blanks out part of the display screen will frustrate the user; and when the AG hardcoat is required, a higher-transmissivity LCD is necessary to improve user viewing. Transmissivity is the measure of how much of the LCD's light both reflected and transmitted- reaches the user through the touch panel. A transmissivity of 80% generally means that an LCD with a 100-nit output will measure 80 nits at the user's viewing point. Typical AG values range from 5 to 10%, but lower values are also available, providing the opportunity to adjust the solution to the application.

Often. there is no perfect solution. One of the factors will emerge as the controlling ele-

ment, and subordinated design parameters will have to be arrived at through compromise.

Under the Sun Many portable electronic devices are used outdoors at least part of the time, so sunlight readability can be a major concern. Power budgets are typically very limited, so reflective and transflective LCDs are u ed almost exclusively, as are clear RTPs.

Recent developments in RTP materials have improved transmissivity beyond 90%, with 93% achieved in production. These gains were made possible through index matching (IM), also called anti-reflection (AR) technology.

Applying 1M coatings to RTP surfaces significantly reduces internal reflections and results in improved visibility of the LCD surface (Fig. 3). The first-surface reflection from the RTP must still be minimized through positioning, but the overall improvement in usability can be quite impressive.

A few portable devices are designed for direct-sunlight readability, even if for a limited amount of time. These device can utilize a strong backlight to achieve the high-lumen output required for sunlight readability, and therefore can use a circularly polarized (CP) RTP for optimum performance. The structure of the CP filter eliminates most external light reflection, ha an AG hardcoat, and allows nearly 80% of the transmissive-mode LCD light to pass through, resulting in a clear display regardless of sun po ition.

Other Directions The future promise further advances in materials and even higher performance. Weight and cost are always primary factor for portable devices, and emerging technologies may help designers create products that are lighter and les expensive.

Plastic technology has been in u e for a relatively short period of time - although it can be found in several applications - so it has not yet developed enough to fulfill expectations . The plastic needs better transmissivity and durability, which will require more materials development.

One of the alternative plastic solutions is the film-on-film touch panel , which eliminates the relatively thick, plastic, back-panel support heet. The LCD urface gla is used for upport instead. Normally, this would be

unacceptable becau e the touch pre ure

Fujitsu l..aboralories

Fig. 4: Fujitsu Laboratories has recently developed miniaturized SAW technology for the ponable-device market. The technology was previously suitable only for statioiUJry largescreen applications.

would alter the liquid-crystal layer thickness, which would change the image. LCDs can be made with an internal structure to prevent this deformation, which makes LCD glass support practical.

Also under development is surface-acoustic-wave (SAW) technology for portable devices. Previously only suited to stationary large-screen applications and comparatively quite expensive, Fujitsu Laboratories has announced the development of a miniaturized SAW-technology touch panel targeting the portable-device market (Fig. 4).

The portable-electronic-device market is changing rapidly as some products merge their functions (mobile telephones and PDAs) and new categories appear (electronic books).

One fact remains certain: Touch input will remain a key factor in the user interface of these devices, especi.ally as their displays become more sophisticated. Advances in touch-input technology are providing designers with a growing range of choices. As a result, we can expect to see smaller and lighter devices that work longer on better batteries and are also easier to view and use. We can expect end users to reward these improved designs by making them successful

in the marketplace. •

CyberToucb designs and manufactures specialty touch screens for the medical, industrial, military

and aerospace industries.

Select from a wide range of off-theshelf touch screens or have us

custom design one for you.

Get in touch with CyberTouch!

[qberTon[h 805.499.5000 • 800.958.4321

cybertouch.com

A View-Navigation System for Hand-Held Portable Displays

Rota Viewnt scrolling technology makes large virtual images accessible to small hand-held devices such as PDAs and mobile telephones.

by David Y. Feinstein

T HERE have been major advances in screen display technology for portable product over the past decade. Higher resolution , improved color quality and backlighting. lower power consumption, and better wideangle viewing have resulted in vastly improved products for the end u er. The e developments have been important contributions to the emergence of smart hand-held devices with increasing levels of ophistication. But one challenge remains: viewing large images , such as Web pages, map , and pread heets, on a small hand-held display.

U ers want access to ever more complex information on devices that remain small and portable. Trying to achieve these mutually incompatible goals by further increasing pixel density necessitates the use of cumbersome optical magnification. Until recently, the only way to view complex graphical information on a mall screen has been to sequentially view selected small areas of a stored virtual image. This inconvenient approach has led to the development of RotoYiew"" crolling technology which offers users a view-navigation y tern that is both intuiti ve and easily controlled by one hand.

David Y. Feinstein is Founder and Presidenr of INNOVENT!ONS, Inc., /0425 Bissonner Sr., HousTon. TX 77099; telephone 28//879-6226,fax 28//879-6415, e-mail: david@ innoventions. com, URL: www.rotoview.com.


Early hand-held device achieved view navigation with an up/down button and an operat ing system (OS) that offered a very limited number of icons. More recent handheld devices have employed a flat joystick for scrolling. but devices with scrolling switche often require two-handed operation. Even when the button are eliminated in futuristic voice- recognition hand-held devices, there is the problem of continually issuing voice commands. Imagine sayi ng, ·'Jeft. up. down, ..... to your PDA. (Picture 400 passenger on an airplane all ay ing this together. )

Tilt! The INNOYENTTO S. Inc. , RotoYiew,,

view-navigation software allows the small display of a hand-held device to scrol l through large virtual images in response to changes in the device's orientation. The user simply tilt the device in the desired direction.

RotoYiew can be visualized as a mall window placed in front of a document larger than the wi ndow. To see beyond the window's boundarie , the viewer naturally wants to tilt the window sideways relative to the document to take a peek at more information. When the

Fig. 1: Tilting a device equipped with RotoView"' scrolling technology navigaTes the display "window" across The image bitmap in the direction oj1he Tilt.

0362-0972/03/1907-022Sl.OO + .00 © SID 2003

u er tilts the device away to get this '·peek." RotoView moves the display window ··across the document"' in the direction of tilt.

Modem tilt sensors enable RotoView to achieve a quick response to the u er' orientation changes. The use of dynamically changing response curves to proces the en or· data eliminates the need to rely on more accurate and expensive sensors. A user control. the view navigation by mean of continuously adjusted hand movements which tilt the display in the desired direction (Fig. I ). This create a closed control loop that alleviates the need for an exact linear relationship between the orientation changes and the re ulting di play navigation.

Choosing the Right Sensors Orientation sensors have been used for many year in virtual-reality systems and in a variety of three-dimensional pointers and 3-D mice. They include microelectromechanical-y tern (MEMS) accelerometers and gyrocopes. magnetic sensor that detect angular

changes relative to the Earth ' magnetic flux , and traditional floatation devices that measure tilts by the movement of a floating medium, imilar to the action of a ball in a liquid. The

floatation devices are generally too low and bulky. and the modern magnetic sen ors ba ed on magneto-resistive elements require a complex setlre et circuitry to keep the sensors in a high- ensitivity tate.

MEMS technology integrates mechanical sen ors and electronics on a common silicon substrate. The mechanical sen ors are formed by etching away silicon or by adding structural layers. The MEMS accelerometer i based on a micromachined polysilicon fom1 that i suspended ela tically above the ba e wafer. The su pended structure moves in re pon e to forces arising from the acceleration of gravity. The device generate a signal related to the acceleration by measuring the differential capacitance between the base wafer and the suspended structure.

The accelerometer can provide a measure of "static" tilt angle relative to the horizon by using the following function: tilt angle = arc sin(A/g). where A is the mea ured acceleration and g is Earth ' s gravitational acceleration. This function indicate that the sensor achieves high sensitivity when the measuring axis is parallel to the Earth's surface and low sensitivity when the measuring axis points toward the Earth· s center

(but there are ways of dealing with this limitation).

At INNOVE TIONS. Inc., we like the MEMS accelerometer for the RotoView application because of their extremely low current- less than 0.4 rnA- and low operational voltage of 3 V. acceptable tilt re olution , adequate response time, ease of interfacing, small size, and low co. t. Analog Devices. lnc., has recently announced the ADXL311 MEMS dual-axis accelerometer that is priced at $2.50 in volume quantities and comes in a 5 x 5 x 2-mm LCC package.

Miniature mechanical gyroscopes detect angular changes arising from the gyroscopic effect that causes the axi of a rotating mass to move in a direction perpendicular to the original angular change. These gyroscopes are too bulky and power hungry to be used in hand-

DUAL AXIS ACCELEROMETER SENSOR

held devices, but MEMS technology ha come to the rescue with the recent introduction of gyroscopes that employ electrostatic fields that vibrate a polysilicon sensing tructure into its resonant state. When the orientation of the device changes. the vibrating structure produce a Coriolis force that is mea ured through changes in capacitance.

The MEMS gyroscopes come in ingle-axi packages that are twice the size of the MEMS acceler6ri1eteis and consume about 8 rnA. Their added complexity, whicl1 ari es partly from the need to generate 16 V internally for the electrostatic fields, results in a cost that is currently 5-10 times that of the MEMS accelerometer . Unlike the accelerometer . MEMS gyroscopes have the advantage of consistent sensitivity at any angle and they do not depend on gravity.

I a a • • • • • a a • a • a a • a a a • a

MODE SWITCH

MEMORY

MICRO CONTROLLER

EXTERNAL INTERFACE

DISPLAY PANEL

Fig. 2: Shown are a block diagram and photograph of the RotoView"' sensor module. Ideally, RotoView should be implemented at the core electronics and operating-systems level (solid lines). If implemented as an add-on module, the sensor interface would connect to the handheld device 's external inte1jace (dotted line).


case study

Optical gyro copes end Ia er light around a fiber-optic ring in both direction . Changes in the interferen e pattern of the t\ o \ a es are u ed to detect rotational movement around the ring through the Sagnac effect.

!though currentl too ex pen i e for a handheld application. optical gyro copes may become affordable' ithin the next 10 years.

System Design The core electronic of a man hand-held device employ at least one microcontroller. a di play controller. and memory torage for progran1 and di play data (Fig. 2). These function are ften integrnted into a single chip or a proces or-and-<:hipset arrangement. (For clarity, other conm10n component , uch as the power ource and the keyboard/ t lu interface. are not hown in the block diagrnm.) The mode witch elect between fixed mode and view-navigation mode and

Sensor's Signal (one axis )

Changes in Orientation

Response Curve

View

0

- 1

0

-1

Navigation o on one axis

-1

·":start

Coarse navigation

can be controlled by a button or by u ing the oftware to detect pecific hand ge tures.

RotoView relies on a dual-axis MEMS accelerometer to detect changes in the spatial orientation at ' hich the de ice is held. The en or is mounted o that it x- andy-axes

generall coincide' ith the "pitch" and "roll" axe of the de ice (an optional z-axis sensor may be u ed to impro e performance). The sensor pro ides analog voltage or duty-cycle modulation (DCM) signals that are respon ive to the tilt of the ensor and hand acceleration along each axis. The sensor interface con ert the e analog signal to digital format.

In the vie -na igation mode. the microcontroller tran ·late the change in pitch and roll orientation to na igation commands that croll the large virtual image stored in the

memory. Thi proce i controlled b the d namically changing re pon e curve of the

Time

Time

.. .. .. . . :. ~ :end Time

. . :t3 : t4

Time

~ Final display position

Fine navigation

Fig. 3: D11rin the view-navigmion ession, a tlynamic response c11rve alllomalically changes the correlation berween tht?' sensor's si nals and view navigation from coorse to jint?.

U lnfommlioo Oisplay 7/(J]

The u er s hand movement are too complex to be described a mere changes in tilt angle; all hand movement include some lateral movements. which produce acceleration components that add to the sensor· output. But as it turns out, this is not a problem. The desired dynamic re pon e curve can be achieved ' ith a well-cho en non-linear dynamic algorithm in conjunction with the natural (and ubliminal) clo ed loop compri ing the u er's

hand movements and the resulting navigation of the display. The loop accommodates both the lateral movements and the actual tilts.

Ideally. RotoView hould be implemented in the core electronic and operating- y tern le el (as indicated by the olid line in Fig. 2). \ ith the sensor interface connecting directly with the microcontroller or chipset via two AID channels. If implemented a an add-on module. the en or interface' ould connect to the hand-held de ice's external interface u ing RS232. USB. or other tandard protocol (dotted line).

Changing the Response Curves The tored re pon e cur es that relate the measured change in de ice orientation to the amount of image area to be navigated must be carefully de igned because they are critical in achie ing u er-friendly navigation. We have found that the be t performance is achieved when the re pon e curve i changed dynamically both in time and magnitude.

One of the disadvantage of a fixed response curve is that the user must perform very small orientation change when trying to achie e fine na igation. This task may be too delicate for most u ers. Dynamically changing re ponse curve enable the view-navigation e ion to start with a large, coarse correlation (Fig. 3). In uch a design. the u er quickly get the di play to the general area of intere t at the start of the navigation e ion . A the session continues. the correlation value become maller. o that the u er can continue to make relatively coarse and easy hand mo ements and till be able to lowly na igate to the final view. The grnph illu trates how a relatively large orientation change during fine navigation (after t3) only lightly reverse the direction of the navigation. while smaller change during coarse navigation (tl- t2) have much larger effect .

Such d namic re ponse curve al o enable the u e of less refined (and therefore cheaper) sen ors. E en if the sen or exhibit abnormal

RED - Y-Axls BLUE - X-Axis

1.0-

0.5-I . . I . . ...

.. ·:.· ... .. ... .· .. ;·:·:: :!:::::::: ·= •' •'• .. .... :···· 0.0- .. . • .. . .. ..

• ' I · .; · ·.···· .... - .... I .... .. . .

I I .. I I

-0.5- I I

I I I I I I I I

-1 .0-' ~ I_

140.0 .

160.0 180.0 20b.o 120.0

t5 t6 t7 t8 t9

• ·~ · • • • Entry Entry Active Exit Command Delay Navigation Command

Fig. 4: When The program encounTers a gesTure corresponding To an enTry command. iT acti

vaTes The navigaTion mode (t5- t6).

non-linearity within certain ranges of its operation, the changing response curves and the user-machine control loop will combine to anive at the correct view.

Users can select or adjust various stored re ponse curves through set-up or change-onthe-fly. The et-up software can associate different response curves with specific applications.

Hand Gestures Control Navigation RotoView utilize the orientation sensor as a smart switch to enter and exit the navigation mode, thus eliminating the need for a mechanical button. The program assigns unique, predefined hand gestures to various commands, which it identifies by monitoring the orientation ensor's signal . The gestural commands comprise a hort set of hand movements, e.g ..

two consecutive fast rolls, selected o the user can easily initiate a command without activating it inadvertently. While the entry and exit commands may be similar. it is more important to ensure that the entry command is less prone to unintentional activation.

When the program encounters a gesture corresponding to an entry command, it acti -

vates the navigation mode (Fig. 4). (The figure is a screen capture from our development system showing the raw sensor data from a dual-axis accelerometer.) The entry command is identified between times t5 and t6. The display remains fixed for a short entry del ay until time t7 to allow the artifacts of the entry hand gesture to sub ide.

The program exits the navigation mode in response to another predefined hand gesture, shown between times t8 and t9. However, by time t9, when the exit command is fully recognized and acted upon, the navigation program may inadvertently alter the final image that was displayed at t8. To solve this problem, a dynamically stored trail of previous navigation states allows the program to restore the view selected just prior to the changes made by the exit hand gesture.

We have also developed two other methods ( elected by a set-up routine) to automatically exi t the navigation mode. The first method sets a fixed time limit for each navigation session, so the user must re-enter the navigation mode if the desired view is not achieved. The second method tem1inates the navigation

mode when the program can not sense further orientation changes (above the normal noise level) for a preset length of time, presumably because the user has reached the desired view. The benefit of the automated exit methods is the elimination of the exit command. However, since these methods may terminate the navigation session before the user reaches the desired location, the re-entry mechanism should be a quick and intuiti ve single-handed operation.

Development Path Cost improvements are essential for a technology aimed at popular low-cost mobile devices. Improvements in the response algorithm tend to reduce the need for expensive accurate sensors .

We have recently seen a major reduction in the cost of MEMS accelerometers. Thus far, we have tested RotoView as an external add-on device, so our implementations have included the costs associated with the external interface circuitry. We believe that the technology will be commercially viable when the sensor is interfaced directly within the core electronics of the hand-held device· s chipset. The new low-cost MEMS accelerometers require only a two-channel ND converter for interfacing.

In the course of development, we have created alternate methods to achieve various aspects of view navigation and control. The methods with the best chance of successful commercial implementation are those that are the most intuiti ve and user-friendly for average users. This will require extensive testing involving a large number of users, followed by proper surveys, to build a good database fo r detem1ining the best methods .

While in recent years we have seen the emergence of combined PDA and communications devices, there are still at least three major platforms- based on the Palm, Windows CE (Pocket PC, SmartPhone), and Symbian operating systems - suitable for RotoView enhancement. This diversity of mobile operating systems and hardware choices requires the imultaneous development of several core solutions. •


Road Show

New technologies and applications are expanding the role of displays in automobiles, helping to inform and entertain both drivers and passengers.

by Robert L. Donofrio

A DVANCES in display technology are changing the ways in wh ich we interact with information in our daily live . Most of us think of di plays in terms of televisions. mobile phones. computer monitors. PDAs. and other electronic devices. It i ea y to overlook - but not overstate- the importance of display technology in automotive applications.

The migration of consumer electronics to vehicles also creates the need for new control and distribution sy terns. such as a digital network for audio/visual y terns. Thi network can be u ed to upport additional devices and functions, including computers and PDAs, as well as infom1ation from ources outside the vehicle, such a global

positioning systems (GPS), entertainment. and data services.

Displays are used in at least ix distinct locations in vehicles (Fig. I ). The most obvi ous is the instrument cluster; this usually includes a speedometer, tachometer, and odometer, along with oil, temperature, and battery gauge or warning light . A second location is the center console, typically home to the stereo sound system; GPS; shifting information: heating. ventil ation, and air-conditioning (HY A C): and warnings about open doors. The rear-view mirror is a third po ition, where a compass. a GPS direction pointer. and even a "backing up" camera

Robert L. Donofrio is President of Display Device Consultants, 6170 Plymouth Rd. , Ann Arbor, M/48105-9531; telephone 7341730-3116./ax 734/665-4211. e-mail: donofrio@ comcasT.com.

26 InformaTion Display 7103

image can occasionally be found. A fourth position is overhead between the front seats, where a backing-up-camera image, a compass, or temperature information can be een. The driver's windshield itself can be used as a projection head-up display for information such as vehicle speed and direction and infrared (IR) image of possible road hazards. Finally, there is growing interest in displays for the back seats which may be located in the back of the center con ole. in the back of the

front seats or their headrests, or even in cei ling fixtures that may fold down for viewing.

ew display application are not just limited to new-model cars. either. There is a growing aftermarket for mobile entertainment and navigation products that typically use 5-9-in . cathode-ray tubes (CRTs) and liquidcry tal display (LCD ).

Automotive applications place pecial demands on displays. Most installation positions require up to 50- 55° (horizontal) view-

Optrex America

Fig. 1: From backseaT enterTainmenT to driver informaTion sysTems. displays play an increasing role in automotive design.

0362-0972/03/1907-026$1.00 + .00 © SID 2003

ing angles. Panels mounted where they are ubject to higher amb ient-light level require

greater luminance in order to maintain acceptable contrast - up to 40% more than for panels mounted in more sheltered location , uch as overhead consoles. Other factors to consider include operating and storage temperature -automobile can get very hot or cold under normal conditions - durability. and pecial user-interface features including touch screens .

The View from Above Clearly. there are abundant opportuni ties for making use of displays in the automobiles of today and the near future. According to Dr. Kimberly Allen of iSuppli/Stanford Resources. the worldwide market for flatpanel displays (FPD ) in automotive applications was $906 million in 200 l and is projected to grow to $1.3 billion in 2006 (Fig. 2). Sales of vacuum fluorescent di plays (VFD ) and light-emitting-diode (LED) displays that are often used in character di plays are expected to decline slightly as they continue to be replaced by passive-matrix LCD and organic light-emitting-diode (OLED) displays. The total number of active-matrix LCD (AMLCD ) will increase from the 2002 value of 8.6 million to $21 million in 2006.

0.9

0.8

0.7

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i:i5 0.5 lt7 c 0.4 Q) :J (ij 0.3 > ,~ " "'

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Year

1.400

1.300

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t/'7 _.,.,

c 0.900 Q) 0.800 ~ ..._ co ~ 0.700

0.600 2000 2001 2002 2003 2004 2005 20

1

06 2007

Year

iSuppiVStanford Resources

Fig. 2: The automotive-display market worldwide is expected to show steady growth through 2006.

It is important to point out that iSuppli/ Stanford Resources tracks only information displays and not backlights. As a result , the actual dollar value for the entire system would be higher.

ln addition to the shift away from VFDs and LEDs toward LCDs, AMLCDs. and OLED

~ ~-

.OJ , ""' ~'

. r>t-~I\ .

2004 2006

Large

Small

~Character

display , the automotive industry is moving toward larger, more versati le displays (Fig. 3). Instrument-cluster and center-console di play are expected not only to convey more information at one time. but to be configurable to show different types of information at different times. The growth in popularity of backseat entertainment sy terns is rapidly increa ing the demand for display sizes in the medium (5-8-in.) range. There is also growing interest in large displays (9 in. and larger).

For the near future, most of these mid- and large-sized display wi ll be LCDs; but in pite of the rapid growth in demand. this will remain a small portion of the overall LCD market. The total LCD revenues in 2000 were $22.4 billion. and by 2006 they will reach about $53 billion, at which point all automotive di plays are expected to account for just $1.3 billion.

Some additional market-research data from Strategic Analysis (via Philips Mobile Display Systems) shows greater demand for rear-seat entertainment sy terns. They project that 1.6 million rear-seat entertainment units wi ll ship in 2006, compared wi th just 250,000 in 2002 . This more than sixfold increase will be driven largely by demand in the U.S. domestic market.

Di playSearch predicts that automoti ve-

iSuppiVStanlord Resources

Fig. 3: Most of the market growth will take place in the medium-si::.ed-display segment, although large displays will increase significamly.

di play hipments in 2006 will be about triple tho e for 2002. The company also anticipates that high-resolution color OLEDs will make their appearance in OEM automotive di plays by 2004.


automotive displays

Yazaki

Fig. 4: Ami-reflectil•e coatings on the VFD in this cemer-console application help reduce reflections from ambient light.

From the Driver's Seat In order to take the pulse of this essential market segment, we contacted many of the major automotive-display supplier to get an update on where they are headed.

Optrex America. Located in Plymouth. Michigan, Optrex is a leading supplier of displays to the automotive industry. In 1981 and 1982. Optrex made the world's first LCD in instrument clusters for the Mit ubishi Cordia and Honda Accord. The company recently tarted an LCD-component assembly plant in Plymouth. Michigan. that uses their tandard cold-cathode-tube (CCT) fluorescent

lamp for backlighting. In May 2002, Optrex licen ed OLED technology from Eastman Kodak Co. for use in passi e-matrix OLED display .

Yazaki North America. Yazaki 's orth American headquarters is located in Canton. Michigan. The Yazaki multimedia display i a 5.8-in . 16:9-aspect-ratio wide color AMLCD with 640 x 350 pixel . The panel luminance is 380 cd/m2

• with viewing angle of ±60° horizontal and ±45° vertical. and an operatingtemperature range of from -30 to +8SOC.

The Yazaki Toyota Prius di play u e a VFD with an anti-reflective (AR) coatingmade with a sol-gel process rather than standard evaporation methods - for the instrument cluster (Fig. 4). The display can thus be expo ed to more ambient light and till maintain good contrast.

Yazaki has shown concept instrument cluster with a two-color I x 2-in. 128 x 64-pixel VFD rated at 1000-2000 cd/m2. The


company also showed a Kodak color activematrix OLED information panel of the same ize. with 512 x 218 pixels and 150 cd/m2.

For the 2007 model year, they will have a 7-in. 16:9-aspect-ratio monitor with a Sharp color LCD for backseat entertainment. featuring a wirele network. Web browser, Windows CE operating system, and support for DVD players and other entertainment device .

Joh nson Controls. Johnson Controls had $20 billion in ales in 2002. They employ 77,000 persons (with about 6000 of them in engineering design and research and development) in 290 locations in 30 countries. ln Michigan, Johnson Controls has displayrelated facilities in the cities of Plymouth and Holland. The company uses more than 6 million LCDs and 3 million VFDs each year.

The Johnson Control 's center-console LCD is a multifunction display used for the radio, clock. and temperature readouts. Twistednematic (T ) and supertwi ted-nematic (STN) LCDs are used for egmented displays. Film-compensated (FSTN) or double-filmcompensated (FFST ) LCD are u ed for dotmatrix displays. and AMLCDs are used for video applications. Some LCDs use an LED backlight, in which light from amber, green, and white LED are di tributed to the panel

using a light guide. The Johnson Controls center-stack display is used by Renaul t and PSA and in the Nissan Primera. The top-ofthe-line product is a full-color AMLCD used for navigation and rear-seat entertainment. The company also uses LCD panels to display images from a rear-facing camera to help the driver back up the vehicle (Fig. 5).

For the future, Johnson Controls engineers are paying attention to OLED technology but do not expect it to be in mass production for automobiles until 2007 or 2008. They al o see the possible use of projection displays as soon as 2006; Johnson Controls is working with Microvision to develop a microelectromechanical (MEM) laser-projection system for both monochrome and full-color displays to compete with LCDs and VFDs.

Durel. Display backlighting becomes essential in applications that cannot rely on ambient lighting for the illumination of a reflective LCD. New environmental standards for mercury-free lighting are pushing display-backlight technology away from the traditional CCf lamp and towards Xe fluorescent lamps and other backlight technologies, including OLEOs, LEDs, and electroluminescent (EL) technologies. EL displays employ either thin films, such as those in

Johnson Controls

Fig. 5: An LCD pane/mounted in an overhead console can provide images from a rear-facing camera to assist the driver when backing up the vehicle.

DureVSiemens VDO

Fig. 6: Thick-fi lm EL backlighTs such as rhese used in a Mercedes console can provide lighring for LCD panels.

Denso's ACTFEL and Planar's EL displays, or thick films, such as those in the backlights made by Durel for the Siemens YDO instrument clusters used in the Mercedes E-Class and CLK models in 2003 (Fig. 6).

In the Mercedes instrument cluster, a floating ring needle is attached to a stepper motor, leaving the center display unobstructed. The Durel EL panel replaces the conventional LED or CCT backlighting for the LCD. According to a Durel representati ve, one EL backlight can replace 6-8 incandescent bulbs or LEOs in an automotive instrument cluster. thus reducing the number of parts and simplifying fabrication.

Philips Mobile Display Systems. Representati ves from Philips Mobile Display Systems see the emergence of the full graphics display in the automotive industry for audio, message center, and entertainment, using AMLCDs, ST -LCDs, and polymer OLEOs (POLEDs). Philips makes LCD modules for JCI, Yisteon, and Delco, and also works directly wi th some auto companies . The ruggedi zing techniques used to make LCDs for the Space Shuttle and Boeing 777 aircraft help improve the displays made for automobiles.

Philips Mobile Display Systems ha demonstrated a new 7-in. AMLCD that is targeted at backseat entertainment and automoti ve infotainment applications.

Luxell and Hyundai LCD. Luxell and Hyundai LCD have reported that they soon will have a 2. 1-in. passive-matrix monochrome OLEO display fo r handheld and automotive applications. expected to be avai lable in 2003.

The Road Ahead The Information Age has extended its reach into all facets of modern life, including the automobile. From navigation and systems information, to sound and video entertainment. to new modes of communication. the need for information display throughout the average au tomobile is growing rapidly. Existing and new technologies are helping engineers design dashboards and consoles that present new information in powerful and accessible ways. The result wi ll be betterinformed drivers and better-entertained passengers, which will translate into a safer and more enjoyable travel experience. •

15 The 23rd International Display Research Conference (IDRC 2003)

PHOENIX, ARIZONA SEPTEMBER 15-18, 2003

• An international conference on disolay research and development aspects of; • Disolay Materials (liquid crvstals smallmolecule and polymer OLEOs phosphors optical compensation films flexible substrates etc.) • Displav modeling Design and Processing • Display Systems and Human Interfaces

17 ~UGUS

The 8th Asian Symposium on Information Display (ASID '03)

NANJING, JIANGSU, CHINA AUGUST 17-20, 2003

• The Asian Symoosium on Information Display fASIDl originated from the joint Jaoan·Korean infer· mation display conference has become one of the major regional information·display conferences sponsored by SID. The puroose of the conference is to provide a friendly and collegiate environment for display researchers especially in the Asian rea ion to present their work and exchange information ASID '03 covers all aspects of display science and technology


and Exhibition

Seattle, Washington


May 23-28, 2004


Active-Matrix LCDs for Mobile Telephones in Japan

The increasingly sophisticated functions of modern mobile telephones require the use of more advanced displays, and the Japanese market leads the way.

by Ryoichi Watanabe and Osamu Tomita

O VER the Ia t few year . liquid-crystal display (LCDs) for mobile applications have improved remarkably in pixel count. brightness, color range, and other characteristics as well. The LCDs u ed in products such a notebook PCs, personal digital as istants (PDAs), digital video camera (DYCs), and. especially. mobile telephones. are required to have small size. low weight. ruggedness, and low power consumption. And, of cour e, they must have high image quality. Becau e markets for portable telephones are increa ing rapidly all over the world, the development of LCDs for mobile telephones is proceeding more rapidly than the development of LCDs for other applications .

Mobile telephones are now being u ed not on ly for voice communications. but also for a variety of other functions (Fig. I). Communications speed in the network infrastructure and individual terminals is increasing. and third-generation (3G) communication service became available in Japan in 2001.

Ryoichi Watanabe is Group Manager of the Cell Design & Engineering Group, Design & Engineering Cemer, Toshiba Matsushita Display Technology Co .. Ltd. , Saitama. Japan. Osamu. Tomita is Group Manager of the Mobile -Use Marketing & Engineering Deparrment, Mobile-Use LCD Division, Toshiba Matsushita Display Technology Co .. Ltd., 1-9-2 Hatara-cho, Fukaya-shi. Saitama, 366-0032, Japan; telephone +81-48-574-5844. fax +81-48-574-2136, e-mail: osamu. [email protected].


In Japan. hort mail and the Internet are the most popular advanced ervices. In March 2002, the number of mobile-telephone Internet sub criber reached 75% of the number of terminals in u e. Commercial transaction . uch as internet hopping and banking, and advanced information services, including streaming video. are among the capabilitie of the e new Internet-capable telephones.

The number of models with built-in cameras is also increas ing, and this is making it possible not only to transmit and receive both tatic and dynamic images. but al o to imple

ment a practical and appealing videophone. These advanced functions require the display of not only characters, but of photographs. maps, and moving picture . To perform these functions effectively, advanced mobile telephones requi re higher-performance LCDs,

Generation I 2G

Communications I --64k bps

speed

I

I

and display performance i improving dramatically.

Trends in LCD Mobile Applications Display mode. Color display were already

dominant in mobile phones in Japan during the first half of 200 I (Fig. 2). The figure hows the percentage of the number of color

LCD models in the Japanese market. By the second half of 200 I , the majority of these color displays were AMLCDs; by the second half of 2002, I 00% of the mobile phones sold in Japan contained color AMLCDs. This trend uggests that the advanced functions included in mobile phones required color AMLCDs for effective implementation.

in the first half of 200 I. tran tlective displays harply outnumbered reflective and transmis ive displays in mobile telephones.

I 2.5G II 3G I

I ~144k bps II ~2M bps I Voiee eommoni"tions, ~ Moving picture. Function short mail, home page. game photographs, GPS TV-phone

Fig. 1: Increases in communications speed make possible more advanced mobile-telephone sen•ices, which require more-capable displays.

0362-0972/0311907-030 1.00 + .00 © SID 2003

2001A Jan. -Jun

2008A Jul.- Dec

2002A Jan .-Jun

20028 J.m.-Jun

Color AMLCDs

Color ST -LCDs

Monochrome LCDs

IOOCC

200 1A Jan-Jun

2008 A Jul-Dec

200:!A J.m.-Jun

20028 Jan-Jun

Transflective

Reflective

Transmissive

Fig. 2: Color AMLCDs had displaced all other display technologies in the Japanese mobile-telephone market by the seco11d half of 2002.

Fig. 3: Transflective displays hal'e dominated the Japanese mobiletelephone market since at least the beginning of200 !.

and the transflect ive optical mode has become even more dominant since then (Fi g. 3). The ascendancy of the transflective optical mode is a direct consequence of its good contra t rat io in both bright and dark ambient-light conditions (Fig. 4, Table I). Transmi sive LCDs exhibit hi gh contrast ratio in dark ambients. but under bright light. such as direct unlight , the ir vis ibil ity decrease . Reflective

LCDs have good vis ibility in bright ambientlight conditions, but ex hibit poor vi ibili ty in dark ambient-l ight conditions. Reflect ive LCDs can display images in bright ambient without either a backl ight or frontlight , offering low power con umption in such conditions. Transfl ecti ve LCDs are well balanced,

1000

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~ 100

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10 100 1.000

and have good visibility in both bright and dark ambients.

Display performance. The number of pixel in supertwisted-nemati c (ST ) and active-matrix LCD in tailed in mobile telephones is increas ing (Fig. 5). ln the first half of 200 1, the most common pixel counts were in the range of 10 I x 122 to 120 x 160; in the fi rst half of 2002 . they were in the range of 128 x 160 to 144 x 176. For di plays with approximately 2 in . diagonals, this works out to be a pixel density of about 11 0 ppi.

How high should pixel density go? Because the normal human vi ual acuity is one minute of arc, most per ons would not be able to resolve pixels spaced more densely

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than 200 ppi at a viewing distance of 40 em ( 16 in .), which is a reasonable distance for cellul ar- telephone use. Therefore, it is reasonable to a sume that the pixel fonnat of 2-in .cl as LCDs will increa e to 240 x 320 (QYGA). Indeed. QVGA displ ays began to appear in the product mix during the second half of 2002.

Both luminance and color reproduction of main tream panels. i.e .. tran flecti ve AMLCDs, increased every 6 months beginning in the fi rst half of 2001 through the first half of 2002 (Table 2). Over thi s period, the luminance increased from 30 to over 100 cd/m2, and the color-reproduction range increased from about I 0% to about 40% of the

240 X 320 (QVGA)

160 X 160 -176 X 220

128 X 160 - 144 x 176

(QCIF)

101 X 122 - 1

(1/16 VGA)

$ 96 X 128 20018 2002A 20028

Jul-Dec Jan.-Jun Jui-Dec

Fig. 4: The popularity of transflective displays is due to the fact that they exhibit a good comrast ratio under all ambiem-illumination conditions.

Fig. 5: In the Japanese marke£, QVGA displays entered £he product mix fo r mobile telephones during the second half of 2002, and are likely 10 dominate in lhefuwre.


mobile-telephone displays

Table 1: Ambient Light and Contrast Ratio

Transmissive

Bright ambient Poor

Dark ambient Excellent

TSC color gamut. Some models have nearly the same values as those in typical notebook PCs. with a luminance of 150 cd/m2 and a color-reproduction range of 50%. We believe that further performance improvements will be required for moving-picture applications uch as televi ion.

LCD Cell Structure As previously indicated. three optical mode are in use (Fig. 6). In the reflective-LCD cell. a polarizer and retarder are tacked on the front side of the cell. and the cell is filled with liquid-crystal material [Fig . 6(a)]. The reflector is formed in ide the cell. The structure produces a high aperture ratio and parallaxfree images.

The requirement for the inner reflector are high reflectance and achromaticity. and the reflected light mu t be diffused. There are two approaches to diffusing the light. One approach i to combine a specular reflector

(a) Reflective LCD

Transflecti ve

Good

Good

Reflective

Good

Fair

with a diffusing layer, while the other is to u e a reflector with dimples that produces both reflection and diffusion from a single layer. The former method results in higher productivity; the latter results in better control of the diffusion.

If the dimples in a dimpled reflector are arranged in a regular lattice. an optical-interference pattern can be generated in bright sunlight. resulting in decreased visibility. If the location of the dimples is randomized, the optical interference can be decreased. An effective way to position the dimples is by using a Fibonacci series, which produces an arrangement that is random along any axis.

The upper side of the cell incorporates a frontlight system which is used as an auxiliary source of illumination. This provides enough illumination to ensure legibilty even in very dark ambients.

The cell structure of transflective LCDs features a polarizer and retarder, both in the

(b) Transflective LCD

Table 2: Brightness and ColorReproduction Range

2001A 2001B 2002A

Luminance (cd/m2) 30 30-50 30-160

Color-reproduction 5-10 10-15 15-40 range(%)

front and rear, and a backlight attached to the rear [Fig. 6(b)]. Two types of pixel structures have been used to realize tran flective LCDs. One is a half-mirror tructure and the other is a structure that divides the pixels into separate transmissive and reflective areas, so that transmissive and reflective performance can be optimized independently. This optimization is performed with multi-color-filter and multi-gap structures .

Multi-color-filter technology was developed to solve a significant and weil-defmed problem in divided pixel cells. Initially, standard color filters were used with dividedpixel-ceil transflective displays. This was fine for the transmissive part of the pixel because light passed through the color filter only once, ju t as in traditional transmissive displays for which such filters had originally been designed. But, in the reflective part of the

(c) Transmissive LCD

Reflective Tran missive light Reflective light Tran missive light

Reflective area backlight

Transmissive area

Fig. 6: Shown are the cell structures of rhe three optical modes used in LCDs for mobile telephones.

32 lnformarion Display 7103

Top view of pixel

Cross-sectional view

Conventional Color Filter

Greenl

Multi-Color-Filter

I D

Greenl

Reflective Area

Transmissive

Fig. 7: In the reflective mode, liglu entering a conventional transflective LCD passes through the LCD layer twice, ll'hile transmissive light passes through it once (left). This makes it impossible to opTimize the performance of the two modes simultaneously. Th e problem is solved by using a multi-gap structure (right).

pixel, the reflected light passes through the color filter twice, with the result that twice the light is absorbed and the display appears much darker in the reflective mode than in the transmissive mode. If we try to solve this problem by reducing the optical density of the color filter. the colors in the tran mis ive pan of the pixel will be insufficiently aturated, i.e. , they will be pale.

Multi-color-filter technology is the solution to this problem (Fig. 7). The color filter for each subpixel is divided into two sections, a low-density area for the reflective pan of the pixel and a higher-density area for transmissive pan. In this way, the color saturation and transmittance of the two areas can be optimized independently rather than being traded off one against the other.

A parallel problem arises with the effective cell gap in transflective displays. A critical design parameter in determining the performance of an LCD is the cell gap, the thicknes

of the gap between the upper and lower pl ates of an LCD, which is filled with liquid-crystal material. In the reflective part of a transflective-LCD pixel , the light traverses the gap twice, so the gap is effectively twice as large as the gap in the transmissive part, even though it is geometrically the same size. The solution is multi-gap technology. which allows the cell gap to be optimized independently for the reflect ive and transmissive parts of the cell (Fig. 8).

The third type of cell structure used in LCDs for portable applications is the transmissive mode [Fig. 6(c)]. This is e entially the same as the transmi sive mode used for notebook-PC and desktop monitors, and is therefore very familiar.

Resolution When a manufacturer sets out to make a highresolution AMLCD - an LCD with a relati vely large number of small pixels packed

Table 3: Specifications of a 2.2-in.-diagonal QVGA LCD

umber of pixels 240 x (RGB) x 320

(QYGA)

Panel size 2.2 in. -diagonal

Resolution 180 ppi

AM LCD device L TPS TFT

Optical mode Transflecti ve

Transmittance 5%

Reflectance 5%

Color-reproduction range 40%

(NTSC ratio)

Contra t ratio (transmissive) 80

Contrast rati o (reflecti ve) 20

lnformmion Display 7103 33

mobile-telephone displays

A : Single-gap structure B : Multi-gap structure

Reflective Transmi ive Reflective Transmissive

twice once

Rl

dl=d l ' dl d2

reflectance transmissive

Fig. 8: In the reflecrive mode, lighr enrering a convenrional 1ransj7ective LCD passes through the LCD layer rwice, ll'hile 1ransmissive light passes through it once (left). This makes ir impossible to oprimi~e 1he performance of the 1wo modes simullaneously. Th e problem is solved by using a multi-gap s/ruc/Ure (right).

0... 0...

"--" c 0 ·.= -= 0 (/} 0)

0:::

250

200

150

100

a-SVL TPS TFT 50

_________________________ ;

0

20,000 40,000 60,000 80,000 100,000

Number of pixels

Fig. 9: As pixel densiry exceeds 150 ppi, if becomes necessary 10 use low-temperature-polysi/icon ( LTPS) TFTs ins1ead of amorphous-silicon ( a-Si) TFTs.


closely together- everal problems must be solved. Because the pixels are small, the area of each pixel devoted to its switching tran i -tor is relatively large and blocks a substantial parts of the light that hould pass through the pixel when the pixel is turned on -resulting in a low aperture ratio. Another problem is that the number of external connections that mu t be made from the AMLCD to the device increase as the pixel count increase , and when there is a high pixel den ity. these connections can become o closely spaced that it becomes difficult to make the connections in a production environment.

Standard amorphou - ilicon (a-Si) TITLCD technology begins to exhibit lower aperture ratio at pixel densities of about !50 ppi. At that density, it becomes nece ary to use low-temperature-poly ilicon (L TPS) TIT . ln the case of a 2.2-in. LCD. the Quarter Common Intermediate Format (QCIF) can be realized with either a-Si or L TPS TITs, but QYGA i easily realized only by LTPS TIT (Fig. 9).

Becau e L TPS is a bener semiconducting material than a-Si. an LTPS TIT can be much maller than an equivalent a-Si TIT, and thus

contributes to a significantly higher aperture ratio for small pixels. L TPS is even fast

Toshiba Matsushita Display Technology Co., Ltd.

Fig. 10: Toshiba MG/sushira Display's 2.2-in.-diameler QVGA transflective display for mobile telephones has 180 ppi and uses LTPS TFTs.

enough to be used to integrate some circuits direct ly on the display gla s. Integrating digital-to-analog converter (DAC) circuits or signal-selector switches on the glass can substantially reduce the number of extemal connection compared to an a-S i TFT-LCD. which requires the same number of connections as it has signal lines. So, LTPS TFTs can achieve easier fabrication and better connection reliability.

A QVGA LCD for Mobile Telephones At Toshiba Matsushita Display Technology, we have developed a QVGA LTPS TFT-LCD (Fig. 10, Table 3). The 2.2-in .-diagonal panel has 76,800 pixels and a pixel den ity of 180 ppi, which results in the high-quality reproduction of detailed images such as maps. The display ' s transflecti ve mode provides good visibility in both bright and dark ambients.

Although QYGA di plays such as this one just began to emerge in the second quarter of 2002 as part of the product mix for mobile telephones in the Japanese market. we are convinced that they represent the future of mobile telephones. The high quality of the mobile telephones is the result not only of improvements in the communications infrastructure and mobile-terminal technology, but also of the continuous improvement of LCDs .

•


and Exhibition

Seattle, Washington


May 23-28, 2004

Please send new product releases or news items to Information Display, c/o Palisades Convention Management, 411 Lafayette Street, 2nd Floor, New York, NY 10003.

17 AUGUST

The 8th Asian Symposium on Information Display (ASID '03)

NANJING, JIANGSU, CHINA AUGUST 17-20, 2003

• The Asian Symoosium on Information Display fASIDl originated from the joint Japan-Korean infor· mation display conference. has become one of the major regional information·disolay conferences soonsored by SID. The puroose of the conference is to provide a friendly and collegiate environment for dis· play researchers especially in the Asian region to present their work and exchange infomnation. ASID '03 covers all aspects of display science and technology

15 SEPTEMBER

The 23rd International Display Research Conference (IDRC 2003)

PHOENIX, ARIZONA SEPTEMBER 15-18, 2003

• An international conference on display research and development aspects of: • Display Materials (liquid crvstals, small molecule and polymer OLEOs phosphors. optical compensation films. flexible substrates etc.) • Disolay modeling, Design and Processing • Display Systems and Human lntertaces

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VG-827: Is a compact, lightweight and low-cost portable video signal generator that maintains compatibi lity with analog output video generators.

VG-826A: Provides up to 8 bits of RGB digital outputs and lowvoltage digital serial outputs (panel link or LVDS), it supports XGA-class (in the 1/1 clock mode) and SXGA-class (in the 1/2 clock mode) timings.

-

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© 3M 2003 Circle no. 13 3NI Innovation

Letter to the Editor: In the February 2003 issue of Information Display, you reported on your visit to Kent. In this article you mentioned that the first spin-off of LCI (Liquid Crystal Institute) was Kent Displays in 1993 and that the founder were Bill Doane and William Manning. I would like to bring to your attention that I was also one of the co-founders and managed the company from its formation until the end of 1995. You should know better!

At the end of 1995, the current management of Kent Displays initiated a legal dispute that is still continuing until today. Many times we discussed how harmful all these prevalent legal fights are to the American display industry. The final result is the colos al decline in the American display manufacturing capabilities and lo s of many good job .

By the way, I graduated with a 4.0 grade average from Kent State University. recei ved the Student Re earch Award from the Sigma Xi Society in recognition of out tanding scientific research in cholesterics , and Bill Doane was my thesi advisor.

Please make the necessary corrections and publish my remarks in the magazine as a letter to the editor.

Best Regards, Zvi Yaniv

Response: A source within Kent Di play confirm that Dr. Y aniv was one of the company's founders. I apologize for the omis ion.

-KJW

Letter to the Editor: This note comments on A. H. Bergman 's article on the F!T CRT display in the October 2002 issue of Information Display. In juxtapo ition with Tom Holzel' "Can Anyone Profit from Selling Wall TVs" in the November issue, it serves to highlight the fact that there is no FPD of adequate performance at an affordable cost so a to enable the transition to

digital HDTV. Prices of shadow-mask CRTs for HDTV also are too high ; and so the transition has stalled. However, the F!T article presents an image generated by a complete display at adequate luminance. So, removing the shadow mask can be made to work. In fact, it provide the only alternative currently on the


scene for the advancement now expected of consumer TV.

It may be beneficial to put the ·'maskless'' color CRT in per pective. The textbox on page 13 of the October issue of ID compares a F'T tube to an index tube. But the F!T tube is an index tube. Its basic mode- phosphor triad tracking - appears in more than a few of the over 300 U.S. patents in the class which covers indexing. Some, such as those from major con umer electronics companie , received publicity. Another, with no publicity, had substantial investment by a major tobacco company. Index patents had to show conformity to the TSC scan direction, but today's technology allows operation at any scan sequence.

The important comparison, which the diagram makes, is the method of color separation. The eparation, or selection, generally associated with "indexing" is sequential color separation (SCS). It was pointed out in "End of the Shadow Mask'' (Information Display. June 1998) that the failure of the " indexing" revival of the 1980s was due to the poor performance of SCS. Its peak currents must be ubstantially higher than is indicated in F!T.

These comparisons. detailed in the Journal of the SID (Vol. 6, No.4, 1998) were made to dynamic color separation (DCS), which was introduced to put CRT performance back where it belongs.

DCS is a broad concept encompassing methods of implementation that cover the full range of CRT scanning options. It accommodates to three-beam, as well as to single-beam operation. Some methods bridge between two versions of color separation . Thus, with three beams, F!T color compares to conventional shadowmask scan and ignal processing, but with an improved performance approaching DCS.

The five-times reduction in beam-current den ity is substantial ly more important than the manipulation of beam astigmatism in reducing electron repulsion. If beam elongation is to reduce peak cathode current, it must be by increased cathode area. In this respect, cold-cathode version (such as that described in '·A ovel Electron Source for CRTs," Information Display, June 2002) should be of special interest becau e the cathode area can be fitted to match the pixel. In that example, with a high electron exit-velocity range, the re ultant high a tigmatism can be corrected.

All versions of DCS and F!T (slightly modified) can have equal H and V re olution

(square pixel). Then, the important factor is that the pixel 's modulation transfer function (MTF) response is near 100% - not the limiting 5% of the shadow mask (and CRT projection). That gives a 2-3 times increase in perceived detail and with performance comparable to the FPD limit and to HDTV' s ultimate promise.

Finally, signal processing i generally not more complicated in the e ystems. It is different but equivalent.

TSC ha served well for almost 60 year . It i past time for change, and it i important that new signal tandards have clear consideration of CRT behavior.

Clayton A. Washburn

Response: According to /D's sources, Philips had seriou intention of commercializing the F!T tube, but, ultimately, when capital expenses and (as it turned out) the minimal improvement in overall TV system cost were considered, Philips decided that the program could not be justified.

-KJW

Letter to David Lieberman What is horizontal and what is vertical? That 's a non-trivial question we tumbled over yesterday, and maybe it is an interesting topic for your column in lnfomation Display.

[I am not] a native Engli h speaker, but that ' not the problem. We were talking about keystone correction. In the past, only trapezoidal distortion from upward projection could be corrected, so that was "keystone correction." ow our company Liesegang electronics GmbH, as well a Pixelworks and Silicon Optix is -able to correct di tortions from upward and sideward projection.

[So] the projection world [now] has to decide how to name these two corrections. One is "horizontal keystone correction"; the other is "vertical keystone correction.' But which one is which? We searched a bit on the Web and could not find an answer, so this is our chance to coin the terms.

To date, the terms are not clearly defined because there exi t two view to keystone correction: the user 's view and the engineer's view. Let' s look at upward projection. The user says, "I correct a distortion from vertical upward projection. so that ' vertical key tone correction." The engineer says, "I have to

letters

manipulate the width of the image, so the algorithm performs horizontal scaling, so that's horizontal keystone correction."

My view is Jet's just agree on something and, as we are developing technology for the user, let' s speak to him in his language. So here's my definition: Vertical keystone correction is the correction of upward projection. Horizontal keystone correction is the correction of sideward projection.

Best regards, Marco Winzker

Manager, ASIC Design Liesegang electronics GmbH

Hannover, Germany e-mail: mwinzker@

liesegang-electronics.com •

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editorial

continued from page 2

ID: But if you are an emerging company, what would make you more attractive to investors?

Ricchiuti: Establish a technology roadmap and milestones, and hit those milestones going six months and a year out. Emerging companies appeal to a very different investor than do established companies. Investors in emerging companies have a larger view than institutional investors, who must show relative safety and quick returns. You saw the crowds here, and that there' s a lot of interest. People do recognize the opportunities; there is clearly an appetite. And there is surely a strong end demand for the products.

Last Story Microvision made a splash a couple of years back with the Nomad"' retinal scanning display it was developing for the military and later applied to industrial applications. That display used a low-power laser diode, so it was a laser beam that was being scanned across the user's retina. Military personnel are not inclined to say "No, sir" when they are instructed to test a new device, but even some of my intrepid journalistic colleagues were heard to say, "Not in my eye you don't."

In fact, the laser intensity was too low to do any harm, but Microvision realized that if they were to develop their technology for consumer products, those products had better not contain lasers. And they don ' t. The company' s new product generation uses three (non-laser) diodes for full color, and the basic Gen 2 engine is one-fifth the size of that in the original monochrome Nomad; the Gen 3 consumer product will be one-tenth the size (see photograph). President Stephen Willey gave the presentation; afterwards, he and Communications Director Matt Nichols showed me the hardware.

44 Infonnation Display 7/03

The first major display target is an electronic viewfinder (EVF) for digital still cameras and camcorders that provides an image with desktop quality, unlike all of the EVFs in use today. The initial target price of this fullcolor module is $50 to OEMs, and it will become cheaper. Microvision is working with Canon in the second phase of a relationship to develop this product. I was shown a prototype built into a camera, and I was impressed with the image quality and stability.

The core of Microvision' s engine is a MEMS device to steer the incoming light beam. If you think about a device containing a single mirror from a Digital Micromirror Device, you will have the general idea. But this mirror traverses in two directions instead of one, and it's larger than the DMD mirrors. Nichols said the device should have infinite lifetime as long as you stay under the shear point of the silicon.

Exit The USDC/Needham Conference was an interesting event, and- as you know if you' ve gotten this far- it gave me a lot to write about without evening mentioning the high-powered keynote addresses or most of the company presentations. But I'll close with one quote from the keynote address by Matt Medeiros, former CEO of Philips Components: "At Philips we should have starved the CRT [of R&D funds] and put that income into AMLCDs. LCD companies must invest in new technologies to move forward."

-KIW

We welcome your comments and suggestions. You can reach me by e-mail at kwerner@ nutmegconsultants.com, by fax at 203/855-9769, or by phone at 203/853-7069. The contents of upcoming issues of ID are available on the ID page at the SID Web site (http:// www.sid. org).

Please send new product releases or news items to Information Display, c/o Palisades Convention Management, 411 Lafayette Street, 2nd Floor, New York, NY 10003.

backlight


polymer OLEOs, it crafted an alliance with SEL to develop active-matrix polymer OLEOs. By the end of the year, the company got its legal ducks in a row and signed a crosslicensing agreement with polymer-OLEO pioneer CDT. And, meanwhile, back in April of 2001 , it had committed $15 million to build a "market development facility" in Santa Barbara to start seeding the OEM community.

Nor was the company wanting in energy in 2002, putting a number of highly significant new relationships into place while managing the progress of the others. And at the 2002 SID International Symposium, the company demoed polymer OLEOs aplenty: monochrome passive-matrix, monochrome activematrix, full-color active-matrix, and a flexible passive-matrix on a plastic substrate.

In the spring of 2002, DuPont Displays, in collaboration with Clare, Inc., announced the availability of driver/controller chips specifically designed and optimized for polymer OLEOs. In the fall, the National Institute of Standards and Technology approved a project under the Advanced Technology Program to fund Sarnoff Corp. to collaboratively develop active-matrix OLEO technology on plastic substrates with Bell Labs and DuPont. In the winter, DuPont announced a agreement with Varitronix, Ltd. , for that Hong Kong display powerhouse to assemble polymer-OLEO modules. And finally, as the year closed, it announced a cross-licensing agreement with UDC, along with a joint development agreement "to create a new generation of soluble OLEO materials and technology" based on phosphorescent OLEOs.

Now what does DuPont Displays have up its sleeve for 2003? I don't know, but you do. (You are reading this in July - well after the 2003 SID International Symposium, Seminar, and Exhibition has closed its doors- but I am writing it well before the doors will even open.) I am hoping that we might start to get a look at some of the invisible relationships DuPont Displays has been forming in the background, the ones that fit the final pieces of the puzzle into place. The ones with customers. Show me cellular phones, PDAs, and Internet appliances. And show them right next to models with LCDs, please. •

David Lieberman is a veteran display journalist living in Massachusetts.

Belarus Chapter News

by Alexander Smirnov

During the last technical meeting of the SID Belarus Chapter, held February 27, 2003, Dr. A. Ilyanok, Director of the Atomic and Molecular Engineering Laboratory, presented an interesting lecture on dynamic design in architecture. This presentation was unusual and somewhat surprising, so I decided to share it with the SID community.

Dr. Ilyanok said that the existing tendencies in architecture and construction are based on the harmony of form, figure, and color spectrum. Thus, leading to a design that is static. Therefore, for a change in style or fashion, the reorganization of buildings and room interiors are required, and this leads to significant expenses. So Dr. Ilyanok offered a new concept in architecture: "dynamic" design or the instantantaneous change of the external and internal appearance of buildings (without changing the form) at will; that is , the decorating and appearance of a building and its internal rooms is made directly with the help of a computer that has a library of pre-existing images or the user's original models. The computer model of the chosen design can instantly be transferred to the walls and windows of rooms without any expense.

The technical realization of this idea is based on a so-called "architectural" display which takes on the role of electronically controlled "wallpaper" and is made of glass blocks with a covering based on nanotechnology. The size 'of the glass blocks can vary from 1 up to 10m2

, and more. By using such blm:ks, it is possible to decorate any room without limit to size or form. It is important that the materials and paints used in displays are inorganic and not reduced under solar ultraviolet radiation. The image on such wallpaper is formed under the action of electrically controlled elements. Thus, the energy is consumed only during image creation (approximately l J/m2

) . Simultaneously, these glass blocks provide thermal and noise isolation.

There were many questions from the audience. Prof. V. Labunov asked how the proposed technical decision differs from the well known "PDLC windows," which are quite expensive now. What will be the approximate cost? Dr. Ilyanok said "It is a flat color dis-

play of an unlimited format, and its cost will be on the order of $100 per square meter. Moreover, in contrast to television and computer displays, dynamic architectural displays operate in reflected light under external illumination; that is, they look like color polygraphic images that do not tire the eyes.

Prof. V. Kourmachev was interested in the additional features of such windows and was informed by Dr. Ilyanok that the architectural displays also operate as electronically controlled filters; in this case, not by the reflection of light, but by the transmission of bght. Such a window can carry out two functions. In the afternoon it transmits solar light. During the evening it takes on the role of a light screen reflecting light inside of a room. Additionally, he noted that this window reflects light in the infrared region, so it can sharply reduce thermal losses in weather. In hot weather, it can reflect solar light and prevent the superfluous heating of rooms.

As for me, I have never participated in such a spirited discussion, and I was interested mostly in addressing the technical issues of such an "architectural" display. "Thank you for your detailed answer, Dr. Ilyanok, but let me ask you once again. What kind of nanostructured material are you using?"

He answered by saying "At present, we have developed a new class of inorganic materials. They are controlled by an external electric current and effectively absorb or reflect light. It is very important that in such materials the charge and, hence, the image be maintained. The static image can be displayed for a long period of time. These can be produced only with nanotechnologies that provide the optimization of ergonomic and electrophysical parameters directly at the molecular level. Such materials can completely replace luminofors."

In conclusion, Dr. Ilyanok proposed to radically change the paradigm of large-sized display construction, switching from a matrixtype light-emitting display to flat RGB displays, to one controlled by external reflected light having a frame frequency of over 75 Hz and self-scanning as a regular feature. Existing technologies do not make room for this paradigm, so new principles of physics, as well as advanced technologies, particularly nanotechnologies, must be adopted.

To explore these issues further, Dr. Ilyanok can be reached at [email protected] or by telephone at +375-29-6-55-83-27.

New SID Senior Members The SID Senior Member Grade Committee is pleased to announce that the following SID members are newly elevated to SID Senior Member status:

Dr. David L. Post, Greater Dayton Chapter Mr. Robert L. Donofrio , Metropolitan

Detroit Chapter Mr. Gus F. Carroll, Bay Area Chapter Mr. Brian H. Berkeley, Bay Area Chapter

Senior Members are those individuals who are recognized to have made significant technical contributions to the advancement of displays and who have demonstrated active participation in the display community and in SID.

Shigeo Mikoshiba, Chair Senior Member Grade Committee

For those of you who wish to be considered for the Senior Member grade, please click "Senior Member Grade" which can be found under "NEW TO THE SITE" on the SID home page, www.sid.org. Also, please see Information Display 18, No. 11, 30 (2002.)

SID Texas Chapter Organizes Session at March APS Meeting The Texas Chapter of the SID coordinated a Focus Session on Nanotechnology for Display Applications during the recent American Physical Society March Meeting in Austin, Texas. This meeting is the largest physics meeting of the year, with an estimated record 5600 talks delivered during the entire meeting. The APS March Meeting is traditionally a showcase for both important fundamental physics and also the type of appbed physics that forms the backbone of modern technology.

There were several sessions devoted to nanotechnology; however, this Focus Session, held on March 5, was devoted to the appbcation of nanotechnology for display applications, probably one of the largest markets for immediate commercialization of nanotechnology. The session was anchored by invited presentations from Karl Amundson of E-Ink Corp., speaking on electrophoretic films for electronic-paper displays, and by Michael Paukshto of Optiva, Inc., speaking on thincrystal-film polarizers. In addition, there were


SID news

five contributed papers to the session, including three on FED applications. As many as 30 sessions were conducted in parallel to this session. Attendance at the Focus Session was about 35.

Richard Fink Chair, Texas Chapter

Richard Fink Receives Texas Chapter Award It was a pleasure to present Richard Fink the Chapter Service A ward of the Texas Chapter of the SID at a Texas Chapter event on January 20, 2003, in Austin, Texas. The award was given in recognition for outstanding service as President of the Texas Chapter and as

organizer of the chapter Nanotechnology Colloquia series that takes place via video conference link between Dallas, Austin, and Houston every other Monday. Richard has also contributed to organizing and serving as editor of the Texas Chapter IP Symposium for the last 4 years. I hope all members join me in congratulating Richard on this achievement and encourage him to continue his contributions to the SID.

Zvi Yaniv Director , Texas Chapter

my turn


We industry folks can count pixels until the cows come home, but in the end, I suspect all that most consumers will really care about is the "duck test," to wit: If a TV set has a big screen and can show HDTV programs, it must be an HDTV - right?

Pete H. Putman is President of ROAM Consulting, Inc., 200-D North St., SuiteD, Doylestown, PA 18901; telephone 2151345-8004, fax 2151345-8007, e-mail: peteputman @projectorexpert.com, URL: www.projector expert. com. He is also a senior contributing editor for Primedia Business Media. ROAM Consulting provides training, marketing communications, and product testing/ development services to manufacturers of projectors, monitors, integrated TVs, and display interfaces.

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Circle no. 18


Symposium, Seminar, and Exhibition

Seattle, Washington


May 23-28, 2004

Acheson Industries, Inc. Ad-Vance Magnetics, Inc. Advance Reproduction Corp. Aerospace Display Systems, LLC AMJ Industries, LLC Amulet Technologies, LLC Applied Concepts, Inc . Astra Products, Inc. A Tl Technologies, Inc. Au GRID Corp. AU Optronics Corp. autronic - Melchers GmbH A very Dennison Microreplication

Brewer Science, Inc . Brimar Ltd.

Candela Instruments Cando Corp. Canon, Inc. CELCO Chi Mei Optoelectronics Corp. Chunghwa Picture Tubes, Ltd. Ciba Specialty Chemicals ClairVoyante Laboratories, lnc. Clinton Electronics Corp. Corning Incorporated Corning Japan K.K. CYRO Industries

Data International DisplaySearch Dontech, lnc. DuPont Displays

E-Ink Corp. ELDECCorp. Electro-Plasma, Inc. Elo TouchSystems, lnc. Endicott Research Group, Inc. ERSO/ITRI

Futaba Corp. , Product Development Center

ODS Gebr. Schmid GmbH & Co. Gennum Corp. GPO Corp.

Hannstar Hitachi, Ltd. Hoya Corp. USA Hunet, Inc.

iFire Technology, Inc. lMT Masken und Teilungen AG Incom, Inc. Industrial Electronic Engineers, Inc.

(lEE) Info Incorporation lnnova Electronics, Inc. Instrument Systems Interface Display & Controls, Inc. iSuppli/Stanford Resources, lnc.

Japan Patent Office

Kent Displays, Inc.

LCD Lighting, Inc. LG.Philips LCD

Micronic Laser Systems AB Microvision, Inc. Mitsubishi Electric Corp. Myson Century, Inc.

National Semiconductor Corp. NEC Corp. Nippon Seiki Co., Ltd. Noritake Itron Corp.

OCLI -A JDS Uniphase Company OES/ITRI Optimax Technology Corp. Optiva, lnc. Optrex America, lnc.

PCS,Inc. Photon Dynamics Photo Research, lnc. Picvue Electronics, Ltd. Pioneer Electronics (USA), Inc. Planar Systems, Inc. Plasmaco, Inc. Polar Vision , Inc. Polytronix , lnc.

Quanta Display, Inc. Quantum Data, Inc.

Reflex.ite Display Optics ROLIC Research Ltd. ROLIC Technologies, Ltd. Royal Philips Electronics

Samsung Electronics Sarnoff Corp. Schott Corp. Sharp Corp. SI Diamond Technology, lnc. Silver Cloud Manufacturing Co. Sony Chemicals Corp. of America Sony Corp. Research Center Supertex, Inc. Symbol Technologies, Inc.

Tannas Electronics Thomas Electronics, Inc. Three-Five Systems, Inc . Tiun Yuan Technology Co. , Ltd. TLC International Toppoly Optoelectronics Corp. Toshiba America Electronic

Components, Inc.

Unaxis Balzars, Ltd. UNIGRAF Universal Display Corp. USA EELY-ECW Optoelectronics, Inc.

Video Electronics Standards Association (YESA)

Yiratec Thin Films, Inc. Yishay-Dale Electronics, Inc. YON ARDENNE Coating Technology

Westar Corp. WINTEK Corp.

ZBD Displays, Ltd.

Astra Systems ....... . .. 36 The Bergquist Co. .......... 8 CyberTouch ... ... . Elo TouchSystems

..21

.. 10 Eyesaver International ... . ..... 35 Grand Pacific Optoelectronics ...... 38 Hong Video Technology .................... 43 Jepico America ... . . .... ....... 6 Optical Filters.... . .... 39

Business and Editorial Offices Palisades Convention Management 41 I Lafayette Street, 2nd Floor New York, NY 10003 Jay Morreale, Managing Editor 212/460-8090 x2 12 Fax: 212/460-5460 [email protected]

Sales Office - Europe George Isaacs 12 Park View Court The Paddock, Eaton Ford St. Neots, Cambridgeshire PE 19 7SD U.K. Phone/Fax: +44-(0)- 1480-2 18400 [email protected]

Sales Office- Japan Ted Asoshina General Manager Echo Japan Corp. Grande Maison Room 303 2-2, Kudan-K.ita 1-chome Chiyoda-ku, Tokyo I 02-0073 Japan +8 1-3-3263-5065 Fax: +81-3-3234-2064 echoj @bonanet.or.jp

Photo Research .. .. ..... ...... .. ..... ... ........... . 9 Quantum Data .... .. .. .. .............................. S Samsung Semiconductor .. ..... ... .. ... ..... C2 Silver Cloud Manufacturing Co .......... 46 Society for Information Display ..... 40,41 3M Optical Systems ..... 7,17,37,C3 VESA... ... ....... .. ....... ..3,C4 Westar Display Technologies ............. 11 Unaxis .. .... .. ..... .... .. ..... ... .... ... . . ... .. 39

Sales Office - U.S.A. Palisades Convention Management 411 Lafayette Street, 2nd Floor New York, NY 10003 Joanne Morgenthal, Sales Manager 212/460-8090 x21 1 Fax: 212/460-5460 [email protected]

Sales Office - Korea Jung-Won Suh Sinsegi Media, Inc. Masters Tower, Room 24 10 553, Dowha-dong Mapo-ku, Seoul 121-040 Korea +82-2-313-1951/2 Fax: +82-2-3 12-7335 sinsegi @sinsegimedia.info

Sales Office - Taiwan Michael Young Trade Media Representative, Inc. 3F, No. 140, San Min Rd. Taipei, Taiwan, R.O.C. +886-2-2763-2438 Fax: +886-2-2545-7868 mediarep @seed.net. tw


DuPont Displays: Forcing the Action

by David Lieberman

They say it takes some 25 years to bring display technology to market, and if we point to the first synthesis of conducting polymers in 1977, it appears that polymer OLEDs are right on track. But what a pace lately! The gathering momentum in both polymer and small-molecule OLEDs over the past few years has been a stunning phenomenon to watch, as tech

nologists sprint to the finish line of fielding viable displays. The level of cooperative effort in the quest for OLEDs has also been extraordinary.

Consider DuPont Displays, for example, just one very visible manifestation of the collaborative spirit in the service of greasing the skids to market. Steve Quindlen, President of the OLED Business there, made manifest the company's strategic intent at the 2002 SID International Symposium to "combine the extensive resources available within DuPont with an entrepreneurial approach driven by speed, innovation, and flexibility; [to] assemble a network of engineers, scientists, and technologists from many companies and technical disciplines to bring new display technologies to market faster ; [to] consolidate and drive broad-based IP; [and to] become a display provider."

DuPont Displays was born in 2000 as the child of a 198-year-old Fortune 500 company, E. I. duPont de Nemours and Company, a parent with deep pockets and vast technical expertise that could be applied to next-generation displays. From its inception, the operation was geared to force the action in OLEDs and bring this new technology to market quickly, leveraging not just the internal strengths of its parent, but external expertise as well.

And the know-how DuPont Displays tapped into has been extensive, cutting across national boundaries and multiple technical disciplines. A partial list of collaborators includes Alien Technology, Cambridge Display Technology (CDT), Clare, Inc., Covion Organic Semiconductors GmbH, Lucent Technologies' Bell Labs, Osram Opto Semiconductors GmbH & Co., Philips Components, Sarnoff Corp. , Semiconductor Energy Laboratory (SEL), Three-Five Systems, Inc., Uniax Corp., Universal Display Corp. (UDC), and Vitex.

The company started its OLED quest in earnest in early 2000 by acquiring Uniax Corp., a 1990 start-up working to commercialize the breakthrough polymer work that had been conducted at the University of California at Santa Barbara. With that solid technical foundation in place, DuPont Displays then set out to put all the pieces of the puzzle in place, forging agreement after agreement as momentum gathered throughout 2001 and beyond, culminating in the shipment of its first polymer-OLED evaluation kits at the end of 2002.

The year 2001 was a stunner. First came the agreement early in the year with Osram Opto Semiconductors GmbH & Co. With this, Osram gained licenses to key Uniax patents as well as a technology transfer of the Uniax manufacturing processes. Shortly thereafter came the critical agreement with RiTEK under which the Taiwanese company began building a high-volume polymer-OLED facility to manufacture displays exclusively for DuPont. And finally, by midyear at the 2001 SID International Symposium, the company announced that it had put two more major relationships in place.

These relationships established both a channel for the present and a road map to the future. For the nonce, DuPont formed a joint venture called Three-D OLED LLC with Three-Five Systems, Inc., to design, assemble, and market passive-matrix polymer-OLED modules. And for coming generations of



The 8th Asian Symposium on Information Display (A~ID '0~). Co t~oi!!.GUniversity, Electro , ~M. J1angsu, 210018 . X +86-25-3363222, URL: w .asid03 .seu.edu.cn. August 17-20, 2003 Nanjing, China

The 12th International Symposium on Advanced Display Technologies & Flowers, 2003. Contact: SID HQ, 408/977-1013, fax -1531 , e-mail: [email protected]. August 25-27,2003 Moscow, Russia

The 23rd International Display Research Conference (IDRC '03). Contact: Ralph Nadell, PCM, 212/460-8090 x203, fax -5460, e-mail: Rnadell@ pcm4ll.com. September 15-18,2003 Phoenix, AZ

The lOth Annual Symposium on Vehicle Displays. Contact: Mark Goldfarb, PCM, 212/460-5460 x202, e-mail : [email protected]. October 13 and 14, 2003 Detroit, MI

The 3rd SID/MAC OLED Research & Technology Conference. Contact: Mark Goldfarb, PCM, 212/460-5460 x202, e-mail: mgoldfarb@pcm411. com. October 24, 2003 New Brunswick, New Jersey

The 11th Color Imaging Conference: Color Science, Engineering, Systems & Applications. Sponsored by lS&T and SID. Contact: SID HQ, 408/977-1013 fax -1531. e-mail: [email protected], www.sid.org. November 4-7,2003 Scottsdalde, AZ

The lOth International Display Workshops (IDW '03). Contact: SID HQ, 408/977-1013, fax -1531 , e-mail: office @sid.org. December 3-5, 2003 Fukuoka, Japan

SID 2004 International Symposium, Seminar & Exhibition. Contact: Mark Goldfarb, PCM, 21 2/460-8090 x202, fax -5460, e-mail: mgoldfarb @ pcm41l.com. May 23-28, 2004 Seattle, W A •

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Current Committees

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VESA Committees

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and Plug and Play

enhancements .

Be there at the beginning .

Participate in the development of

ground-breaking display industry

standards with VESA's (Video

Electron ic Standards Assoc iation)

international team of industry

experts.

First ones to know

Join over 120 member companies

from around the world who

already benefi t from advanced

knowledge of new technology

standards.

As a member, you are

invited to take part in monthly

committee and workgroup

meetings, or simply be the first to

access resulting technical papers

and industry standards .

Display industry leaders

Steadfastly dedicated to

innovation and market growth,

VESA members lead through their

visionary efforts to develop and

promote open standards.

VESA See our vi rtual trade show

at VESA.org

920 Hillview Court, Ste . 140, Milpitas, CA 95035 408 .957.9270 fax 408 .957.9277 sales@vesa .org

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Portable Displays: Resolution ••• What's...

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